CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Xylem - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy","wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"2d5f56a1-c6f4-445a-bc49-430f500a6f17","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Xylem","wgTitle":"Xylem","wgCurRevisionId":1282031809,"wgRevisionId":1282031809,"wgArticleId":46675,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["CS1 German-language sources (de)","Webarchive template wayback links","CS1 maint: multiple names: authors list","CS1 Hungarian-language sources (hu)","All articles with dead external links","Articles with dead external links from October 2023","Articles with permanently dead external links","CS1 Latin-language sources (la)","CS1: long volume value","Articles with short description","Short description is different from Wikidata","All articles with unsourced statements","Articles with unsourced statements from January 2025","Articles with unsourced statements from March 2019","Articles with unsourced statements from October 2023","Articles with unsourced statements from November 2022","Articles with unsourced statements from February 2015","Commons category link from Wikidata","Plant anatomy","Plant cells","Plant physiology","Tissues (biology)"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Xylem","wgRelevantArticleId":46675,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":60000,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q122811","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGELevelingUpEnabledForUser":false}; RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.quicksurveys.init","ext.growthExperiments.SuggestedEditSession"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.22"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Xylem_and_phloem_diagram.svg/1200px-Xylem_and_phloem_diagram.svg.png"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="1211"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Xylem_and_phloem_diagram.svg/800px-Xylem_and_phloem_diagram.svg.png"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="807"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Xylem_and_phloem_diagram.svg/640px-Xylem_and_phloem_diagram.svg.png"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="646"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Xylem - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Xylem"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Xylem&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Xylem"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="auth.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Xylem rootpage-Xylem skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" title="Main menu" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li><li id="n-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages"><span>Special pages</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=Xylem" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=Xylem" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=Xylem" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=Xylem" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Structure" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Structure"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Structure</span> </div> </a> <ul id="toc-Structure-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Primary_and_secondary_xylem" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Primary_and_secondary_xylem"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Primary and secondary xylem</span> </div> </a> <ul id="toc-Primary_and_secondary_xylem-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Main_function_–_upwards_water_transport" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Main_function_–_upwards_water_transport"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Main function – upwards water transport</span> </div> </a> <button aria-controls="toc-Main_function_–_upwards_water_transport-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Main function – upwards water transport subsection</span> </button> <ul id="toc-Main_function_–_upwards_water_transport-sublist" class="vector-toc-list"> <li id="toc-Cohesion-tension_theory" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Cohesion-tension_theory"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Cohesion-tension theory</span> </div> </a> <ul id="toc-Cohesion-tension_theory-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Measurement_of_pressure" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Measurement_of_pressure"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Measurement of pressure</span> </div> </a> <ul id="toc-Measurement_of_pressure-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Evolution" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Evolution"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Evolution</span> </div> </a> <ul id="toc-Evolution-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Development" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Development"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Development</span> </div> </a> <button aria-controls="toc-Development-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Development subsection</span> </button> <ul id="toc-Development-sublist" class="vector-toc-list"> <li id="toc-Protoxylem_and_metaxylem" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Protoxylem_and_metaxylem"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Protoxylem and metaxylem</span> </div> </a> <ul id="toc-Protoxylem_and_metaxylem-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Patterns_of_protoxylem_and_metaxylem" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Patterns_of_protoxylem_and_metaxylem"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>Patterns of protoxylem and metaxylem</span> </div> </a> <ul id="toc-Patterns_of_protoxylem_and_metaxylem-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-History" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>History</span> </div> </a> <ul id="toc-History-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Explanatory_notes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Explanatory_notes"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Explanatory notes</span> </div> </a> <ul id="toc-Explanatory_notes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>References</span> </div> </a> <button aria-controls="toc-References-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle References subsection</span> </button> <ul id="toc-References-sublist" class="vector-toc-list"> <li id="toc-Citations" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Citations"> <div class="vector-toc-text"> <span class="vector-toc-numb">9.1</span> <span>Citations</span> </div> </a> <ul id="toc-Citations-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-General_references" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#General_references"> <div class="vector-toc-text"> <span class="vector-toc-numb">9.2</span> <span>General references</span> </div> </a> <ul id="toc-General_references-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" title="Table of Contents" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Xylem</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 68 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-68" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">68 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%86%D8%B3%D9%8A%D8%AC_%D9%88%D8%B9%D8%A7%D8%A6%D9%8A_%D8%AE%D8%B4%D8%A8%D9%8A" title="نسيج وعائي خشبي – Arabic" lang="ar" hreflang="ar" data-title="نسيج وعائي خشبي" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Xilema" title="Xilema – Asturian" lang="ast" hreflang="ast" data-title="Xilema" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%9C%E0%A6%BE%E0%A6%87%E0%A6%B2%E0%A7%87%E0%A6%AE" title="জাইলেম – Bangla" lang="bn" hreflang="bn" data-title="জাইলেম" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%9A%D1%81%D1%96%D0%BB%D0%B5%D0%BC%D0%B0" title="Ксілема – Belarusian" lang="be" hreflang="be" data-title="Ксілема" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-be-x-old mw-list-item"><a href="https://be-tarask.wikipedia.org/wiki/%D0%9A%D1%81%D1%8B%D0%BB%D0%B5%D0%BC%D0%B0" title="Ксылема – Belarusian (Taraškievica orthography)" lang="be-tarask" hreflang="be-tarask" data-title="Ксылема" data-language-autonym="Беларуская (тарашкевіца)" data-language-local-name="Belarusian (Taraškievica orthography)" class="interlanguage-link-target"><span>Беларуская (тарашкевіца)</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9A%D1%81%D0%B8%D0%BB%D0%B5%D0%BC" title="Ксилем – Bulgarian" lang="bg" hreflang="bg" data-title="Ксилем" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Ksilem" title="Ksilem – Bosnian" lang="bs" hreflang="bs" data-title="Ksilem" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Xilema" title="Xilema – Catalan" lang="ca" hreflang="ca" data-title="Xilema" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Xyl%C3%A9m" title="Xylém – Czech" lang="cs" hreflang="cs" data-title="Xylém" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-cy mw-list-item"><a href="https://cy.wikipedia.org/wiki/Sylem" title="Sylem – Welsh" lang="cy" hreflang="cy" data-title="Sylem" data-language-autonym="Cymraeg" data-language-local-name="Welsh" class="interlanguage-link-target"><span>Cymraeg</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Xylem" title="Xylem – Danish" lang="da" hreflang="da" data-title="Xylem" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Xylem" title="Xylem – German" lang="de" hreflang="de" data-title="Xylem" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Ks%C3%BCleem" title="Ksüleem – Estonian" lang="et" hreflang="et" data-title="Ksüleem" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%9E%CF%8D%CE%BB%CF%89%CE%BC%CE%B1" title="Ξύλωμα – Greek" lang="el" hreflang="el" data-title="Ξύλωμα" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Xilema" title="Xilema – Spanish" lang="es" hreflang="es" data-title="Xilema" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Ksilemo" title="Ksilemo – Esperanto" lang="eo" hreflang="eo" data-title="Ksilemo" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Xilema" title="Xilema – Basque" lang="eu" hreflang="eu" data-title="Xilema" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%A8%D8%A7%D9%81%D8%AA_%DA%86%D9%88%D8%A8%DB%8C" title="بافت چوبی – Persian" lang="fa" hreflang="fa" data-title="بافت چوبی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Xyl%C3%A8me" title="Xylème – French" lang="fr" hreflang="fr" data-title="Xylème" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Xil%C3%A9im" title="Xiléim – Irish" lang="ga" hreflang="ga" data-title="Xiléim" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gv mw-list-item"><a href="https://gv.wikipedia.org/wiki/Sylem" title="Sylem – Manx" lang="gv" hreflang="gv" data-title="Sylem" data-language-autonym="Gaelg" data-language-local-name="Manx" class="interlanguage-link-target"><span>Gaelg</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Xilema" title="Xilema – Galician" lang="gl" hreflang="gl" data-title="Xilema" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EB%AC%BC%EA%B4%80%EB%B6%80" title="물관부 – Korean" lang="ko" hreflang="ko" data-title="물관부" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%B2%D5%B6%D5%A1%D6%83%D5%A1%D5%B5%D5%BF" title="Բնափայտ – Armenian" lang="hy" hreflang="hy" data-title="Բնափայտ" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%9C%E0%A4%BE%E0%A4%87%E0%A4%B2%E0%A4%AE" title="जाइलम – Hindi" lang="hi" hreflang="hi" data-title="जाइलम" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Ksilem" title="Ksilem – Croatian" lang="hr" hreflang="hr" data-title="Ksilem" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Pembuluh_kayu" title="Pembuluh kayu – Indonesian" lang="id" hreflang="id" data-title="Pembuluh kayu" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Xilema" title="Xilema – Italian" lang="it" hreflang="it" data-title="Xilema" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A2%D7%A6%D7%94" title="עצה – Hebrew" lang="he" hreflang="he" data-title="עצה" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-jv mw-list-item"><a href="https://jv.wikipedia.org/wiki/Xilem" title="Xilem – Javanese" lang="jv" hreflang="jv" data-title="Xilem" data-language-autonym="Jawa" data-language-local-name="Javanese" class="interlanguage-link-target"><span>Jawa</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%A5%E1%83%A1%E1%83%98%E1%83%9A%E1%83%94%E1%83%9B%E1%83%90" title="ქსილემა – Georgian" lang="ka" hreflang="ka" data-title="ქსილემა" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%9A%D1%81%D0%B8%D0%BB%D0%B5%D0%BC%D0%B0" title="Ксилема – Kazakh" lang="kk" hreflang="kk" data-title="Ксилема" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ht mw-list-item"><a href="https://ht.wikipedia.org/wiki/Zil%C3%A8m" title="Zilèm – Haitian Creole" lang="ht" hreflang="ht" data-title="Zilèm" data-language-autonym="Kreyòl ayisyen" data-language-local-name="Haitian Creole" class="interlanguage-link-target"><span>Kreyòl ayisyen</span></a></li><li class="interlanguage-link interwiki-ku mw-list-item"><a href="https://ku.wikipedia.org/wiki/Ks%C3%AElem" title="Ksîlem – Kurdish" lang="ku" hreflang="ku" data-title="Ksîlem" data-language-autonym="Kurdî" data-language-local-name="Kurdish" class="interlanguage-link-target"><span>Kurdî</span></a></li><li class="interlanguage-link interwiki-ky mw-list-item"><a href="https://ky.wikipedia.org/wiki/%D0%9A%D1%81%D0%B8%D0%BB%D0%B5%D0%BC%D0%B0" title="Ксилема – Kyrgyz" lang="ky" hreflang="ky" data-title="Ксилема" data-language-autonym="Кыргызча" data-language-local-name="Kyrgyz" class="interlanguage-link-target"><span>Кыргызча</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Xylema" title="Xylema – Latin" lang="la" hreflang="la" data-title="Xylema" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Mediena_(audinys)" title="Mediena (audinys) – Lithuanian" lang="lt" hreflang="lt" data-title="Mediena (audinys)" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Xil%C3%A9m" title="Xilém – Hungarian" lang="hu" hreflang="hu" data-title="Xilém" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%9A%D1%81%D0%B8%D0%BB%D0%B5%D0%BC" title="Ксилем – Macedonian" lang="mk" hreflang="mk" data-title="Ксилем" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%B8%E0%B5%88%E0%B4%B2%E0%B4%82" title="സൈലം – Malayalam" lang="ml" hreflang="ml" data-title="സൈലം" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Xilem" title="Xilem – Malay" lang="ms" hreflang="ms" data-title="Xilem" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Xyleem" title="Xyleem – Dutch" lang="nl" hreflang="nl" data-title="Xyleem" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja badge-Q17437798 badge-goodarticle mw-list-item" title="good article badge"><a href="https://ja.wikipedia.org/wiki/%E6%9C%A8%E9%83%A8" title="木部 – Japanese" lang="ja" hreflang="ja" data-title="木部" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Vedvev" title="Vedvev – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Vedvev" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Vedvev" title="Vedvev – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Vedvev" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-om mw-list-item"><a href="https://om.wikipedia.org/wiki/Zaayilamii" title="Zaayilamii – Oromo" lang="om" hreflang="om" data-title="Zaayilamii" data-language-autonym="Oromoo" data-language-local-name="Oromo" class="interlanguage-link-target"><span>Oromoo</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Ksilema" title="Ksilema – Uzbek" lang="uz" hreflang="uz" data-title="Ksilema" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-pa mw-list-item"><a href="https://pa.wikipedia.org/wiki/%E0%A8%9C%E0%A8%BC%E0%A8%BE%E0%A8%88%E0%A8%B2%E0%A8%AE" title="ਜ਼ਾਈਲਮ – Punjabi" lang="pa" hreflang="pa" data-title="ਜ਼ਾਈਲਮ" data-language-autonym="ਪੰਜਾਬੀ" data-language-local-name="Punjabi" class="interlanguage-link-target"><span>ਪੰਜਾਬੀ</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Drewno_(botanika)" title="Drewno (botanika) – Polish" lang="pl" hreflang="pl" data-title="Drewno (botanika)" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Xilema" title="Xilema – Portuguese" lang="pt" hreflang="pt" data-title="Xilema" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Xilem" title="Xilem – Romanian" lang="ro" hreflang="ro" data-title="Xilem" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9A%D1%81%D0%B8%D0%BB%D0%B5%D0%BC%D0%B0" title="Ксилема – Russian" lang="ru" hreflang="ru" data-title="Ксилема" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Xylem" title="Xylem – Simple English" lang="en-simple" hreflang="en-simple" data-title="Xylem" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Ksilem" title="Ksilem – Slovenian" lang="sl" hreflang="sl" data-title="Ksilem" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-so mw-list-item"><a href="https://so.wikipedia.org/wiki/Maydhax" title="Maydhax – Somali" lang="so" hreflang="so" data-title="Maydhax" data-language-autonym="Soomaaliga" data-language-local-name="Somali" class="interlanguage-link-target"><span>Soomaaliga</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/Ksilem" title="Ksilem – Serbian" lang="sr" hreflang="sr" data-title="Ksilem" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Ksilem" title="Ksilem – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Ksilem" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-su mw-list-item"><a href="https://su.wikipedia.org/wiki/Xilem" title="Xilem – Sundanese" lang="su" hreflang="su" data-title="Xilem" data-language-autonym="Sunda" data-language-local-name="Sundanese" class="interlanguage-link-target"><span>Sunda</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Xylem" title="Xylem – Swedish" lang="sv" hreflang="sv" data-title="Xylem" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%95%E0%AE%BE%E0%AE%B4%E0%AF%8D" title="காழ் – Tamil" lang="ta" hreflang="ta" data-title="காழ்" data-language-autonym="தமிழ்" data-language-local-name="Tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B9%80%E0%B8%99%E0%B8%B7%E0%B9%89%E0%B8%AD%E0%B9%84%E0%B8%A1%E0%B9%89" title="เนื้อไม้ – Thai" lang="th" hreflang="th" data-title="เนื้อไม้" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tg mw-list-item"><a href="https://tg.wikipedia.org/wiki/%D0%9A%D1%81%D0%B8%D0%BB%D0%B5%D0%BC%D0%B0" title="Ксилема – Tajik" lang="tg" hreflang="tg" data-title="Ксилема" data-language-autonym="Тоҷикӣ" data-language-local-name="Tajik" class="interlanguage-link-target"><span>Тоҷикӣ</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Ksilem" title="Ksilem – Turkish" lang="tr" hreflang="tr" data-title="Ksilem" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9A%D1%81%D0%B8%D0%BB%D0%B5%D0%BC%D0%B0" title="Ксилема – Ukrainian" lang="uk" hreflang="uk" data-title="Ксилема" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/M%E1%BA%A1ch_g%E1%BB%97" title="Mạch gỗ – Vietnamese" lang="vi" hreflang="vi" data-title="Mạch gỗ" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/%E6%9C%A8%E8%B4%A8%E9%83%A8" title="木质部 – Wu" lang="wuu" hreflang="wuu" data-title="木质部" data-language-autonym="吴语" data-language-local-name="Wu" class="interlanguage-link-target"><span>吴语</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E6%9C%A8%E8%B3%AA%E9%83%A8" title="木質部 – Cantonese" lang="yue" hreflang="yue" data-title="木質部" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E6%9C%A8%E8%B4%A8%E9%83%A8" title="木质部 – Chinese" lang="zh" hreflang="zh" data-title="木质部" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q122811#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Xylem" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Xylem" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Xylem"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Xylem&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Xylem&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Xylem"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Xylem&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Xylem&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Xylem" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Xylem" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Xylem&oldid=1282031809" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Xylem&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=Xylem&id=1282031809&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FXylem"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FXylem"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=Xylem&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Xylem&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:Xylem" hreflang="en"><span>Wikimedia Commons</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q122811" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Water transport tissue in vascular plants</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For the company, see <a href="/wiki/Xylem_Inc." title="Xylem Inc.">Xylem Inc.</a></div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:Xylem_and_phloem_diagram.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Xylem_and_phloem_diagram.svg/320px-Xylem_and_phloem_diagram.svg.png" decoding="async" width="320" height="323" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Xylem_and_phloem_diagram.svg/481px-Xylem_and_phloem_diagram.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Xylem_and_phloem_diagram.svg/640px-Xylem_and_phloem_diagram.svg.png 2x" data-file-width="337" data-file-height="340" /></a><figcaption>Xylem (blue) transports water and minerals from the roots upwards.</figcaption></figure> <p><b>Xylem</b> is one of the two types of transport <a href="/wiki/Tissue_(biology)" title="Tissue (biology)">tissue</a> in <a href="/wiki/Vascular_plant" title="Vascular plant">vascular plants</a>, the other being <a href="/wiki/Phloem" title="Phloem">phloem</a>; both of these are part of the <a href="/wiki/Vascular_bundle" title="Vascular bundle">vascular bundle</a>. The basic function of the xylem is to transport <a href="/wiki/Water" title="Water">water</a> upward from the roots to parts of the plants such as stems and leaves, but it also transports <a href="/wiki/Plant_nutrition" title="Plant nutrition">nutrients</a>.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> The word <i>xylem</i> is derived from the <a href="/wiki/Ancient_Greek" title="Ancient Greek">Ancient Greek</a> word <span lang="grc"><a href="https://en.wiktionary.org/wiki/%CE%BE%CF%8D%CE%BB%CE%BF%CE%BD#Ancient_Greek" class="extiw" title="wikt:ξύλον">ξύλον</a></span> (<span title="Ancient Greek transliteration" lang="grc-Latn"><i>xúlon</i></span>), meaning "<a href="/wiki/Wood" title="Wood">wood</a>"; the best-known xylem tissue is wood, though it is found throughout a plant.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> The term was introduced by <a href="/wiki/Carl_N%C3%A4geli" title="Carl Nägeli">Carl Nägeli</a> in 1858.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Structure">Structure</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=1" title="Edit section: Structure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1062633282">@media all and (max-width:720px){.mw-parser-output .content .thumb>div:not(.thumbinner){display:flex;justify-content:center;flex-wrap:wrap;align-content:flex-start;flex-direction:column}}body.skin-vector .mw-parser-output div.thumb>div:not(.thumbinner){font-size:94%;text-align:center;overflow:hidden;min-width:100px}body.skin-minerva .mw-parser-output div.thumb>div:not(.thumbinner){margin:0 auto;max-width:100%!important}</style> <div class="thumb tright"> <div style="display:table;"> <span typeof="mw:File/Frameless"><a href="/wiki/File:Xylem_cells.svg" class="mw-file-description" title="Diagrammatic structure of xylem cells"><img alt="Diagrammatic structure of xylem cells" src="//upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Xylem_cells.svg/400px-Xylem_cells.svg.png" decoding="async" width="400" height="470" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Xylem_cells.svg/600px-Xylem_cells.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Xylem_cells.svg/800px-Xylem_cells.svg.png 2x" data-file-width="400" data-file-height="470" /></a></span><div class="thumbcaption" style="display:table-caption;caption-side:bottom;box-sizing:border-box;">Diagrammatic structure of xylem cells </div> </div> </div> <p>The most distinctive xylem <a href="/wiki/Cell_(biology)" title="Cell (biology)">cells</a> are the long tracheary elements that transport water. <a href="/wiki/Tracheid" title="Tracheid">Tracheids</a> and <a href="/wiki/Vessel_element" title="Vessel element">vessel elements</a> are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called <i>vessels</i>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </p><p>Xylem also contains two other type of cells: <a href="/wiki/Ground_tissue#Parenchyma" title="Ground tissue">parenchyma</a> and <a href="/wiki/Ground_tissue#Fibres" title="Ground tissue">fibers</a>.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>Xylem can be found: </p> <ul><li>in <a href="/wiki/Vascular_bundle" title="Vascular bundle">vascular bundles</a>, present in non-woody plants and non-woody parts of woody plants</li> <li>in secondary xylem, laid down by a <a href="/wiki/Meristem" title="Meristem">meristem</a> called the <a href="/wiki/Vascular_cambium" title="Vascular cambium">vascular cambium</a> in woody plants</li> <li>as part of a <a href="/wiki/Stele_(biology)" title="Stele (biology)">stelar arrangement</a> not divided into bundles, as in many <a href="/wiki/Fern" title="Fern">ferns</a>.</li></ul> <p>In transitional stages of plants with <a href="/wiki/Secondary_growth" title="Secondary growth">secondary growth</a>, the first two categories are not mutually exclusive, although usually a vascular bundle will contain <i>primary xylem</i> only. </p><p>The branching pattern exhibited by xylem follows <a href="/wiki/Murray%27s_law" title="Murray's law">Murray's law</a>.<sup id="cite_ref-mcculloh_8-0" class="reference"><a href="#cite_note-mcculloh-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Primary_and_secondary_xylem">Primary and secondary xylem</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=2" title="Edit section: Primary and secondary xylem"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><b>Primary xylem</b> is formed during primary growth from <a href="/wiki/Procambium" class="mw-redirect" title="Procambium">procambium</a>. It includes protoxylem and metaxylem. Metaxylem develops after the protoxylem but before secondary xylem. Metaxylem has wider vessels and tracheids than protoxylem.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup> </p><p><b>Secondary xylem</b> is formed during secondary growth from <a href="/wiki/Vascular_cambium" title="Vascular cambium">vascular cambium</a>. Although secondary xylem is also found in members of the <a href="/wiki/Gymnosperm" title="Gymnosperm">gymnosperm</a> groups <a href="/wiki/Gnetophyta" title="Gnetophyta">Gnetophyta</a> and <a href="/wiki/Ginkgophyta" class="mw-redirect" title="Ginkgophyta">Ginkgophyta</a> and to a lesser extent in members of the <a href="/wiki/Cycadophyta" class="mw-redirect" title="Cycadophyta">Cycadophyta</a>, the two main groups in which secondary xylem can be found are: </p> <ol><li><a href="/wiki/Conifers" class="mw-redirect" title="Conifers">conifers</a> (<i>Coniferae</i>): there are approximately 600 known species of conifers.<sup id="cite_ref-Judd_9-0" class="reference"><a href="#cite_note-Judd-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> All species have secondary xylem, which is relatively uniform in structure throughout this group. Many conifers become tall trees: the secondary xylem of such trees is used and marketed as <a href="/wiki/Softwood" title="Softwood">softwood</a>.</li> <li><a href="/wiki/Angiosperms" class="mw-redirect" title="Angiosperms">angiosperms</a> (<i>Angiospermae</i>): there are approximately 250,000<sup id="cite_ref-Judd_9-1" class="reference"><a href="#cite_note-Judd-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> known species of angiosperms. Within this group secondary xylem is rare in the <a href="/wiki/Monocots" class="mw-redirect" title="Monocots">monocots</a>.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> Many non-monocot angiosperms become trees, and the secondary xylem of these is used and marketed as <a href="/wiki/Hardwood" title="Hardwood">hardwood</a>.</li></ol> <div class="mw-heading mw-heading2"><h2 id="Main_function_–_upwards_water_transport"><span id="Main_function_.E2.80.93_upwards_water_transport"></span>Main function – upwards water transport</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=3" title="Edit section: Main function – upwards water transport"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The xylem, vessels and tracheids of the roots, stems and leaves are interconnected to form a continuous system of water-conducting channels reaching all parts of the plants. The system transports water and soluble mineral nutrients from the roots throughout the plant. It is also used to replace water lost during <a href="/wiki/Transpiration" title="Transpiration">transpiration</a> and photosynthesis. Xylem <a href="/wiki/Plant_sap" class="mw-redirect" title="Plant sap">sap</a> consists mainly of water and inorganic ions, although it can also contain a number of organic chemicals as well. The transport is passive, not powered by energy spent by the <a href="/wiki/Vessel_elements" class="mw-redirect" title="Vessel elements">tracheary</a> elements themselves, which are dead by maturity and no longer have living contents. Transporting sap upwards becomes more difficult as the height of a plant increases and upwards transport of water by xylem is considered to limit the maximum height of trees.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> Three phenomena cause xylem sap to flow: </p> <ul><li><b><a href="/wiki/Pressure_flow_hypothesis" title="Pressure flow hypothesis">Pressure flow hypothesis</a></b>: Sugars produced in the leaves and other green tissues are kept in the phloem system, creating a <a href="/wiki/Water_potential" title="Water potential">solute pressure</a> differential versus the xylem system carrying a far lower load of <a href="/wiki/Solute" class="mw-redirect" title="Solute">solutes</a>—water and minerals. The phloem pressure can rise to several MPa,<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> far higher than atmospheric pressure. Selective inter-connection between these systems allows this high solute concentration in the phloem to draw xylem fluid upwards by negative pressure.</li> <li><span class="anchor" id="Transpirational_pull"></span><b><a href="/wiki/Transpiration" title="Transpiration">Transpirational</a> pull</b>: Similarly, the <a href="/wiki/Evaporation" title="Evaporation">evaporation</a> of <a href="/wiki/Water" title="Water">water</a> from the surfaces of <a href="/wiki/Mesophyll" class="mw-redirect" title="Mesophyll">mesophyll</a> cells to the atmosphere also creates a negative pressure at the top of a plant. This causes millions of minute <a href="/wiki/Meniscus_(liquid)" title="Meniscus (liquid)">menisci</a> to form in the mesophyll cell wall. The resulting <a href="/wiki/Surface_tension" title="Surface tension">surface tension</a> causes a negative pressure or <a href="/wiki/Tension_(physics)" title="Tension (physics)">tension</a> in the xylem that pulls the water from the roots and soil.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup></li> <li><b><a href="/wiki/Root_pressure" title="Root pressure">Root pressure</a></b>: If the water potential of the root cells is more negative than that of the <a href="/wiki/Soil" title="Soil">soil</a>, usually due to high concentrations of solute, water can move by <a href="/wiki/Osmosis" title="Osmosis">osmosis</a> into the root from the soil. This causes a positive pressure that forces sap up the xylem towards the leaves. In some circumstances, the sap will be forced from the leaf through a <a href="/wiki/Hydathode" title="Hydathode">hydathode</a> in a phenomenon known as <a href="/wiki/Guttation" title="Guttation">guttation</a>. Root pressure is highest in the morning before the opening of stomata and allow transpiration to begin. Different plant species can have different root pressures even in a similar environment; examples include up to 145 kPa in <i><a href="/wiki/Vitis_riparia" title="Vitis riparia">Vitis riparia</a></i> but around zero in <i><a href="/wiki/Celastrus_orbiculatus" title="Celastrus orbiculatus">Celastrus orbiculatus</a></i>.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup></li></ul> <p>The primary force that creates the <a href="/wiki/Capillary_action" title="Capillary action">capillary action</a> movement of water upwards in plants is the adhesion between the water and the surface of the xylem conduits.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> Capillary action provides the force that establishes an equilibrium configuration, balancing gravity. When transpiration removes water at the top, the flow is needed to return to the equilibrium.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup> </p><p>Transpirational pull results from the evaporation of water from the surfaces of <a href="/wiki/Cell_(biology)" title="Cell (biology)">cells</a> in the <a href="/wiki/Leaves" class="mw-redirect" title="Leaves">leaves</a>. This evaporation causes the surface of the water to recess into the <a href="https://en.wiktionary.org/wiki/pore" class="extiw" title="wikt:pore">pores</a> of the <a href="/wiki/Cell_wall" title="Cell wall">cell wall</a>. By <a href="/wiki/Capillary_action" title="Capillary action">capillary action</a>, the water forms concave menisci inside the pores. The high surface tension of water pulls the <a href="https://en.wiktionary.org/wiki/Concavity" class="extiw" title="wikt:Concavity">concavity</a> outwards, generating enough <a href="/wiki/Force" title="Force">force</a> to lift water as high as a hundred meters from ground level to a <a href="/wiki/Tree" title="Tree">tree</a>'s highest branches. </p><p>Transpirational pull requires that the vessels transporting the water be very small in diameter; otherwise, <a href="/wiki/Cavitation" title="Cavitation">cavitation</a> would break the water column. And as water <a href="/wiki/Evaporates" class="mw-redirect" title="Evaporates">evaporates</a> from leaves, more is drawn up through the plant to replace it. When the water pressure within the xylem reaches extreme levels due to low water input from the roots (if, for example, the soil is dry), then the gases come out of solution and form a bubble – an <a href="/wiki/Embolism" title="Embolism">embolism</a> forms, which will spread quickly to other adjacent cells, unless <a href="/wiki/Pit_(botany)" title="Pit (botany)">bordered pits</a> are present (these have a plug-like structure called a torus, that seals off the opening between adjacent cells and stops the embolism from spreading). Even after an embolism has occurred, plants are able to refill the xylem and restore the functionality.<sup id="cite_ref-Nardini2011_16-0" class="reference"><a href="#cite_note-Nardini2011-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Cohesion-tension_theory">Cohesion-tension theory</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=4" title="Edit section: Cohesion-tension theory"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <i>cohesion-tension theory</i> is a theory of <a href="/wiki/Intermolecular_attraction" class="mw-redirect" title="Intermolecular attraction">intermolecular attraction</a> that explains the process of water flow upwards (against the force of <a href="/wiki/Gravity" title="Gravity">gravity</a>) through the xylem of plants. It was proposed in 1894 by <a href="/wiki/John_Joly" title="John Joly">John Joly</a> and <a href="/wiki/Henry_Horatio_Dixon" title="Henry Horatio Dixon">Henry Horatio Dixon</a>.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> Despite numerous objections,<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> this is the most widely accepted theory for the transport of water through a plant's vascular system based on the classical research of Dixon-Joly (1894), Eugen Askenasy (1845–1903) (1895),<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> and Dixon (1914,1924).<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p><p>Water is a <a href="/wiki/Polar_molecule" class="mw-redirect" title="Polar molecule">polar molecule</a>. When two water molecules approach one another, the slightly negatively charged <a href="/wiki/Oxygen" title="Oxygen">oxygen</a> atom of one forms a <a href="/wiki/Hydrogen_bond" title="Hydrogen bond">hydrogen bond</a> with a slightly positively charged <a href="/wiki/Hydrogen" title="Hydrogen">hydrogen</a> atom in the other. This attractive force, along with other <a href="/wiki/Intermolecular_force" title="Intermolecular force">intermolecular forces</a>, is one of the principal factors responsible for the occurrence of <a href="/wiki/Surface_tension" title="Surface tension">surface tension</a> in liquid water. It also allows plants to draw water from the root through the xylem to the leaf.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup> </p><p>Water is constantly lost through transpiration from the leaf. When one water molecule is lost another is pulled along by the processes of cohesion and tension. Transpiration pull, utilizing <a href="/wiki/Capillary_action" title="Capillary action">capillary action</a> and the inherent surface tension of water, is the primary mechanism of water movement in plants. However, it is not the only mechanism involved. Any use of water in leaves forces water to move into them.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup> </p><p><a href="/wiki/Transpiration" title="Transpiration">Transpiration</a> in leaves creates tension (differential pressure) in the cell walls of mesophyll cells. Because of this tension, water is being pulled up from the roots into the leaves, helped by <a href="/wiki/Cohesion_(chemistry)" title="Cohesion (chemistry)">cohesion</a> (the pull between individual water molecules, due to hydrogen bonds) and <a href="/wiki/Adhesion" title="Adhesion">adhesion</a> (the stickiness between water molecules and the <a href="/wiki/Hydrophilic" class="mw-redirect" title="Hydrophilic">hydrophilic</a> cell walls of plants). This mechanism of water flow works because of <a href="/wiki/Water_potential" title="Water potential">water potential</a> (water flows from high to low potential), and the rules of simple <a href="/wiki/Diffusion" title="Diffusion">diffusion</a>.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </p><p>Over the past century, there has been a great deal of research regarding the mechanism of xylem sap transport; today, most plant scientists continue to agree that the <i>cohesion-tension theory</i> best explains this process, but multiforce theories that hypothesize several alternative mechanisms have been suggested, including longitudinal cellular and xylem <a href="/wiki/Osmotic_pressure" title="Osmotic pressure">osmotic pressure</a> <a href="/wiki/Gradient" title="Gradient">gradients</a>, axial potential gradients in the vessels, and gel- and gas-bubble-supported interfacial gradients.<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-tyree1997_27-0" class="reference"><a href="#cite_note-tyree1997-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Measurement_of_pressure">Measurement of pressure</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=5" title="Edit section: Measurement of pressure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Pressurebomb.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/34/Pressurebomb.svg/330px-Pressurebomb.svg.png" decoding="async" width="290" height="202" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/34/Pressurebomb.svg/435px-Pressurebomb.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/34/Pressurebomb.svg/580px-Pressurebomb.svg.png 2x" data-file-width="394" data-file-height="274" /></a><figcaption>A diagram showing the setup of a <a href="/wiki/Pressure_bomb" class="mw-redirect" title="Pressure bomb">pressure bomb</a></figcaption></figure> <p>Until recently, the differential pressure (suction) of transpirational pull could only be measured indirectly, by applying external pressure with a <a href="/wiki/Pressure_bomb" class="mw-redirect" title="Pressure bomb">pressure bomb</a> to counteract it.<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> When the technology to perform direct measurements with a pressure probe was developed, there was initially some doubt about whether the classic theory was correct, because some workers were unable to demonstrate negative pressures. More recent measurements do tend to validate the classic theory, for the most part. Xylem transport is driven by a combination<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> of transpirational pull from above and <a href="/wiki/Root_pressure" title="Root pressure">root pressure</a> from below, which makes the interpretation of measurements more complicated. </p> <div class="mw-heading mw-heading2"><h2 id="Evolution">Evolution</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=6" title="Edit section: Evolution"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Xylem appeared early in the history of terrestrial plant life. Fossil plants with anatomically preserved xylem are known from the <a href="/wiki/Silurian" title="Silurian">Silurian</a> (more than 400 million years ago), and trace fossils resembling individual xylem cells may be found in earlier <a href="/wiki/Ordovician" title="Ordovician">Ordovician</a> rocks.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (March 2019)">citation needed</span></a></i>]</sup> The earliest true and recognizable xylem consists of <a href="/wiki/Tracheid" title="Tracheid">tracheids</a> with a helical-annular reinforcing layer added to the <a href="/wiki/Cell_wall" title="Cell wall">cell wall</a>. This is the only type of xylem found in the earliest vascular plants, and this type of cell continues to be found in the <i>protoxylem</i> (first-formed xylem) of all living groups of vascular plants. Several groups of plants later developed <a href="/wiki/Pit_(botany)" title="Pit (botany)">pitted</a> tracheid cells independently through <a href="/wiki/Convergent_evolution" title="Convergent evolution">convergent evolution</a>. In living plants, pitted tracheids do not appear in development until the maturation of the <i>metaxylem</i> (following the <i>protoxylem</i>).<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup> </p><p>In most plants, pitted <a href="/wiki/Tracheid" title="Tracheid">tracheids</a> function as the primary transport cells. The other type of vascular element, found in angiosperms, is the <a href="/wiki/Vessel_element" title="Vessel element">vessel element</a>. Vessel elements are joined end to end to form vessels in which water flows unimpeded, as in a pipe. The presence of <b>xylem vessels</b> (also called <b>trachea</b><sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup>) is considered to be one of the key innovations that led to the success of the <a href="/wiki/Angiosperms" class="mw-redirect" title="Angiosperms">angiosperms</a>.<sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> However, the occurrence of vessel elements is not restricted to angiosperms, and they are absent in some archaic or "basal" lineages of the angiosperms: (e.g., <a href="/wiki/Amborellaceae" class="mw-redirect" title="Amborellaceae">Amborellaceae</a>, <a href="/wiki/Tetracentraceae" class="mw-redirect" title="Tetracentraceae">Tetracentraceae</a>, <a href="/wiki/Trochodendraceae" title="Trochodendraceae">Trochodendraceae</a>, and <a href="/wiki/Winteraceae" title="Winteraceae">Winteraceae</a>), and their secondary xylem is described by <a href="/wiki/Arthur_Cronquist" title="Arthur Cronquist">Arthur Cronquist</a> as "primitively vesselless". Cronquist considered the vessels of <i><a href="/wiki/Gnetum" title="Gnetum">Gnetum</a></i> to be convergent with those of angiosperms.<sup id="cite_ref-32" class="reference"><a href="#cite_note-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> Whether the absence of vessels in basal angiosperms is a <a href="/wiki/Cladistics#Definitions" title="Cladistics">primitive</a> condition is contested, the alternative hypothesis states that vessel elements originated in a precursor to the angiosperms and were subsequently lost. </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Ficusxylem.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Ficusxylem.jpg/330px-Ficusxylem.jpg" decoding="async" width="290" height="162" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Ficusxylem.jpg/500px-Ficusxylem.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Ficusxylem.jpg/960px-Ficusxylem.jpg 2x" data-file-width="1771" data-file-height="991" /></a><figcaption>Photos showing xylem elements in the shoot of a fig tree (<i>Ficus alba</i>): crushed in hydrochloric acid, between slides and cover slips</figcaption></figure> <p>To photosynthesize, plants must absorb CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> from the atmosphere. However, this comes at a price: while stomata are open to allow CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> to enter, water can evaporate.<sup id="cite_ref-Sperry2003_33-0" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Water is lost much faster than CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> is absorbed, so plants need to replace it, and have developed systems to transport water from the moist soil to the site of photosynthesis.<sup id="cite_ref-Sperry2003_33-1" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Early plants sucked water between the walls of their cells, then evolved the ability to control water loss (and CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> acquisition) through the use of stomata. Specialized water transport tissues soon evolved in the form of hydroids, tracheids, then secondary xylem, followed by an endodermis and ultimately vessels.<sup id="cite_ref-Sperry2003_33-2" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>The high CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> levels of Silurian-Devonian times, when plants were first colonizing land, meant that the need for water was relatively low. As CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> was withdrawn from the atmosphere by plants, more water was lost in its capture, and more elegant transport mechanisms evolved.<sup id="cite_ref-Sperry2003_33-3" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> As water transport mechanisms, and waterproof cuticles, evolved, plants could survive without being continually covered by a film of water. This transition from <a href="/wiki/Poikilohydry" title="Poikilohydry">poikilohydry</a> to <a href="/wiki/Homoiohydry" title="Homoiohydry">homoiohydry</a> opened up new potential for colonization.<sup id="cite_ref-Sperry2003_33-4" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Plants then needed a robust internal structure that held long narrow channels for transporting water from the soil to all the different parts of the above-soil plant, especially to the parts where photosynthesis occurred.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup> </p><p>During the Silurian, CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> was readily available, so little water needed expending to acquire it. By the end of the Carboniferous, when CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> levels had lowered to something approaching today's, around 17 times more water was lost per unit of CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> uptake.<sup id="cite_ref-Sperry2003_33-5" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> However, even in these "easy" early days, water was at a premium, and had to be transported to parts of the plant from the wet soil to avoid <a href="/wiki/Desiccation" title="Desiccation">desiccation</a>. This early water transport took advantage of the <i>cohesion-tension</i> mechanism inherent in water. Water has a tendency to diffuse to areas that are drier, and this process is accelerated when water can be <a href="/wiki/Capillary_action" title="Capillary action">wicked</a> along a fabric with small spaces. In small passages, such as that between the plant cell walls (or in tracheids), a column of water behaves like rubber – when molecules evaporate from one end, they pull the molecules behind them along the channels. Therefore, transpiration alone provided the driving force for water transport in early plants.<sup id="cite_ref-Sperry2003_33-6" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> However, without dedicated transport vessels, the cohesion-tension mechanism cannot transport water more than about 2 cm, severely limiting the size of the earliest plants.<sup id="cite_ref-Sperry2003_33-7" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> This process demands a steady supply of water from one end, to maintain the chains; to avoid exhausting it, plants developed a waterproof <a href="/wiki/Plant_cuticle" title="Plant cuticle">cuticle</a>. Early cuticle may not have had pores but did not cover the entire plant surface, so that gas exchange could continue.<sup id="cite_ref-Sperry2003_33-8" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> However, dehydration at times was inevitable; early plants cope with this by having a lot of water stored between their cell walls, and when it comes to it sticking out the tough times by putting life "on hold" until more water is supplied.<sup id="cite_ref-Sperry2003_33-9" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Banded_tube.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/96/Banded_tube.jpg/250px-Banded_tube.jpg" decoding="async" width="220" height="89" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/96/Banded_tube.jpg/330px-Banded_tube.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/96/Banded_tube.jpg/500px-Banded_tube.jpg 2x" data-file-width="805" data-file-height="325" /></a><figcaption>A <a href="/wiki/Banded_tube" title="Banded tube">banded tube</a> from the late Silurian/early Devonian. The bands are difficult to see on this specimen, as an opaque carbonaceous coating conceals much of the tube. Bands are just visible in places on the left half of the image – click on the image for a larger view. Scale bar: 20 μm</figcaption></figure> <p>To be free from the constraints of small size and constant moisture that the parenchymatic transport system inflicted, plants needed a more efficient water transport system. During the <a href="/wiki/Llandovery_epoch" class="mw-redirect" title="Llandovery epoch">early Silurian</a>, they developed specialized cells, which were <a href="/wiki/Lignin" title="Lignin">lignified</a> (or bore similar chemical compounds)<sup id="cite_ref-Sperry2003_33-10" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> to avoid implosion; this process coincided with cell death, allowing their innards to be emptied and water to be passed through them.<sup id="cite_ref-Sperry2003_33-11" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> These wider, dead, empty cells were a million times more conductive than the inter-cell method, giving the potential for transport over longer distances, and higher CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> diffusion rates. </p><p>The earliest macrofossils to bear water-transport tubes are Silurian plants placed in the genus <i><a href="/wiki/Cooksonia_(plant)" class="mw-redirect" title="Cooksonia (plant)">Cooksonia</a></i>.<sup id="cite_ref-Edwards1992_34-0" class="reference"><a href="#cite_note-Edwards1992-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> The early Devonian pretracheophytes <i><a href="/wiki/Aglaophyton" title="Aglaophyton">Aglaophyton</a></i> and <i><a href="/wiki/Horneophyton" title="Horneophyton">Horneophyton</a></i> have structures very similar to the <a href="/wiki/Hydroid_(botany)" title="Hydroid (botany)">hydroids</a> of modern mosses. Plants continued to innovate new ways of reducing the resistance to flow within their cells, thereby increasing the efficiency of their water transport. Bands on the walls of tubes, in fact apparent from the early Silurian onwards,<sup id="cite_ref-Niklas1983_35-0" class="reference"><a href="#cite_note-Niklas1983-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> are an early improvisation to aid the easy flow of water.<sup id="cite_ref-Niklas1985_36-0" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> Banded tubes, as well as tubes with pits in their walls, were lignified<sup id="cite_ref-Niklas1980_37-0" class="reference"><a href="#cite_note-Niklas1980-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> and, when they form single celled conduits, are considered to be <i>tracheids</i>. These, the "next generation" of transport cell design, have a more rigid structure than hydroids, allowing them to cope with higher levels of water pressure.<sup id="cite_ref-Sperry2003_33-12" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Tracheids may have a single evolutionary origin, possibly within the hornworts,<sup id="cite_ref-Qiu2006_38-0" class="reference"><a href="#cite_note-Qiu2006-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> uniting all tracheophytes (but they may have evolved more than once).<sup id="cite_ref-Sperry2003_33-13" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>Water transport requires regulation, and dynamic control is provided by <a href="/wiki/Stoma" title="Stoma">stomata</a>.<sup id="cite_ref-gk_39-0" class="reference"><a href="#cite_note-gk-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> By adjusting the amount of gas exchange, they can restrict the amount of water lost through transpiration. This is an important role where water supply is not constant, and indeed stomata appear to have evolved before tracheids, being present in the non-vascular hornworts.<sup id="cite_ref-Sperry2003_33-14" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>An <a href="/wiki/Endodermis" title="Endodermis">endodermis</a> probably evolved during the Silu-Devonian, but the first fossil evidence for such a structure is Carboniferous.<sup id="cite_ref-Sperry2003_33-15" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> This structure in the roots covers the water transport tissue and regulates ion exchange (and prevents unwanted pathogens etc. from entering the water transport system). The endodermis can also provide an upwards pressure, forcing water out of the roots when transpiration is not enough of a driver. </p><p>Once plants had evolved this level of controlled water transport, they were truly homoiohydric, able to extract water from their environment through root-like organs rather than relying on a film of surface moisture, enabling them to grow to much greater size.<sup id="cite_ref-Sperry2003_33-16" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> As a result of their independence from their surroundings, they lost their ability to survive desiccation – a costly trait to retain.<sup id="cite_ref-Sperry2003_33-17" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>During the Devonian, maximum xylem diameter increased with time, with the minimum diameter remaining pretty constant.<sup id="cite_ref-Niklas1985_36-1" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> By the middle Devonian, the tracheid diameter of some plant lineages (<a href="/wiki/Zosterophyllophytes" class="mw-redirect" title="Zosterophyllophytes">Zosterophyllophytes</a>) had plateaued.<sup id="cite_ref-Niklas1985_36-2" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> Wider tracheids allow water to be transported faster, but the overall transport rate depends also on the overall cross-sectional area of the xylem bundle itself.<sup id="cite_ref-Niklas1985_36-3" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> The increase in vascular bundle thickness further seems to correlate with the width of plant axes, and plant height; it is also closely related to the appearance of leaves<sup id="cite_ref-Niklas1985_36-4" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> and increased stomatal density, both of which would increase the demand for water.<sup id="cite_ref-Sperry2003_33-18" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p><span class="anchor" id="XylemCavitation"></span> While wider tracheids with robust walls make it possible to achieve higher water transport tensions, this increases the likelihood of cavitation.<sup id="cite_ref-Sperry2003_33-19" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Cavitation occurs when a bubble of air forms within a vessel, breaking the bonds between chains of water molecules and preventing them from pulling more water up with their cohesive tension. A tracheid, once cavitated, cannot have its embolism removed and return to service (except in a few advanced angiosperms<sup id="cite_ref-40" class="reference"><a href="#cite_note-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-41" class="reference"><a href="#cite_note-41"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup> which have developed a mechanism of doing so). Therefore, it is well worth plants' while to avoid cavitation occurring. For this reason, <a href="/wiki/Pit_(botany)" title="Pit (botany)">pits</a> in tracheid walls have very small diameters, to prevent air entering and allowing bubbles to nucleate. Freeze-thaw cycles are a major cause of cavitation. Damage to a tracheid's wall almost inevitably leads to air leaking in and cavitation, hence the importance of many tracheids working in parallel.<sup id="cite_ref-Sperry2003_33-20" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>Once cavitation has occurred, plants have a range of mechanisms to contain the damage.<sup id="cite_ref-Sperry2003_33-21" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Small pits link adjacent conduits to allow fluid to flow between them, but not air – although these pits, which prevent the spread of embolism, are also a major cause of them.<sup id="cite_ref-Sperry2003_33-22" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> These pitted surfaces further reduce the flow of water through the xylem by as much as 30%.<sup id="cite_ref-Sperry2003_33-23" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> The diversification of xylem strand shapes with tracheid network topologies increasingly resistant to the spread of embolism likely facilitated increases in plant size and the colonization of drier habitats during the <a href="/wiki/Devonian_explosion" class="mw-redirect" title="Devonian explosion">Devonian radiation</a>.<sup id="cite_ref-42" class="reference"><a href="#cite_note-42"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup> Conifers, by the Jurassic, developed <a href="/wiki/Pit_(botany)#Types_of_pits" title="Pit (botany)">bordered pits</a> had valve-like structures to isolate cavitated elements. These <a href="/wiki/Pit_(botany)#Torus_and_margo" title="Pit (botany)">torus-margo</a> structures have an impermeable disc (torus) suspended by a permeable membrane (margo) between two adjacent pores. When a tracheid on one side depressurizes, the disc is sucked into the pore on that side, and blocks further flow.<sup id="cite_ref-Sperry2003_33-24" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Other plants simply tolerate cavitation. For instance, oaks grow a ring of wide vessels at the start of each spring, none of which survive the winter frosts.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (October 2023)">citation needed</span></a></i>]</sup> Maples use root pressure each spring to force sap upwards from the roots, squeezing out any air bubbles.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (November 2022)">citation needed</span></a></i>]</sup> </p><p>Growing to height also employed another trait of tracheids – the support offered by their lignified walls. Defunct tracheids were retained to form a strong, woody stem, produced in most instances by a secondary xylem. However, in early plants, tracheids were too mechanically vulnerable, and retained a central position, with a layer of tough <a href="/wiki/Sclerenchyma" class="mw-redirect" title="Sclerenchyma">sclerenchyma</a> on the outer rim of the stems.<sup id="cite_ref-Sperry2003_33-25" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Even when tracheids do take a structural role, they are supported by sclerenchymatic tissue. </p><p>Tracheids end with walls, which impose a great deal of resistance on flow;<sup id="cite_ref-Niklas1985_36-5" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> vessel members have perforated end walls, and are arranged in series to operate as if they were one continuous vessel.<sup id="cite_ref-Niklas1985_36-6" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> The function of end walls, which were the default state in the Devonian, was probably to avoid <a href="/wiki/Embolism" title="Embolism">embolisms</a>. An embolism is where an air bubble is created in a tracheid. This may happen as a result of freezing, or by gases dissolving out of solution. Once an embolism is formed, it usually cannot be removed (but see later); the affected cell cannot pull water up, and is rendered useless. </p><p>End walls excluded, the tracheids of prevascular plants were able to operate under the same hydraulic conductivity as those of the first vascular plant, <i>Cooksonia</i>.<sup id="cite_ref-Niklas1985_36-7" class="reference"><a href="#cite_note-Niklas1985-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> </p><p>The size of tracheids is limited as they comprise a single cell; this limits their length, which in turn limits their maximum useful diameter to 80 μm.<sup id="cite_ref-Sperry2003_33-26" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Conductivity grows with the fourth power of diameter, so increased diameter has huge rewards; <i>vessel elements</i>, consisting of a number of cells, joined at their ends, overcame this limit and allowed larger tubes to form, reaching diameters of up to 500 μm, and lengths of up to 10 m.<sup id="cite_ref-Sperry2003_33-27" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p><p>Vessels first evolved during the dry, low CO<sub style="font-size: 80%;vertical-align: -0.35em">2</sub> periods of the late Permian, in the horsetails, ferns and <a href="/wiki/Selaginellales" class="mw-redirect" title="Selaginellales">Selaginellales</a> independently, and later appeared in the mid Cretaceous in angiosperms and gnetophytes.<sup id="cite_ref-Sperry2003_33-28" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Vessels allow the same cross-sectional area of wood to transport around a hundred times more water than tracheids!<sup id="cite_ref-Sperry2003_33-29" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> This allowed plants to fill more of their stems with structural fibers, and also opened a new niche to <a href="/wiki/Vine" title="Vine">vines</a>, which could transport water without being as thick as the tree they grew on.<sup id="cite_ref-Sperry2003_33-30" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> Despite these advantages, tracheid-based wood is a lot lighter, thus cheaper to make, as vessels need to be much more reinforced to avoid cavitation.<sup id="cite_ref-Sperry2003_33-31" class="reference"><a href="#cite_note-Sperry2003-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Development">Development</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=7" title="Edit section: Development"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Xylem_Development.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Xylem_Development.svg/130px-Xylem_Development.svg.png" decoding="async" width="130" height="519" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Xylem_Development.svg/195px-Xylem_Development.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Xylem_Development.svg/260px-Xylem_Development.svg.png 2x" data-file-width="188" data-file-height="750" /></a><figcaption>Patterns of xylem development: xylem in brown; arrows show direction of development from protoxylem to metaxylem.</figcaption></figure> <p>Xylem development can be described by four terms: <i>centrarch, exarch, endarch</i> and <i>mesarch</i>. As it develops in young plants, its nature changes from <i>protoxylem</i> to <i>metaxylem</i> (i.e. from <i>first xylem</i> to <i>after xylem</i>). The patterns in which protoxylem and metaxylem are arranged are essential in studying plant morphology.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (January 2025)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading3"><h3 id="Protoxylem_and_metaxylem"><span class="anchor" id="Proto"></span>Protoxylem and metaxylem</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=8" title="Edit section: Protoxylem and metaxylem"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>As a young <a href="/wiki/Vascular_plant" title="Vascular plant">vascular plant</a> grows, one or more strands of primary xylem form in its stems and roots. The first xylem to develop is called 'protoxylem'. In appearance, protoxylem is usually distinguished by narrower vessels formed of smaller cells. Some of these cells have walls that contain thickenings in the form of rings or helices. Functionally, protoxylem can extend: the cells can grow in size and develop while a stem or root is elongating. Later, 'metaxylem' develops in the strands of xylem. Metaxylem vessels and cells are usually larger; the cells have thickenings typically either in the form of ladderlike transverse bars (scalariform) or continuous sheets except for holes or pits (pitted). Functionally, metaxylem completes its development after elongation ceases when the cells no longer need to grow in size.<sup id="cite_ref-FosterGifford1974_43-0" class="reference"><a href="#cite_note-FosterGifford1974-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-44" class="reference"><a href="#cite_note-44"><span class="cite-bracket">[</span>44<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Patterns_of_protoxylem_and_metaxylem">Patterns of protoxylem and metaxylem</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=9" title="Edit section: Patterns of protoxylem and metaxylem"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>There are four primary patterns to the arrangement of protoxylem and metaxylem in stems and roots. </p> <ul><li><i>Centrarch</i> refers to the case in which the primary xylem forms a single cylinder in the center of the stem and develops from the center outwards. The protoxylem is thus found in the central core, and the metaxylem is in a cylinder around it.<sup id="cite_ref-45" class="reference"><a href="#cite_note-45"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup> This pattern was common in early land plants, such as "<a href="/wiki/Rhyniophyte" title="Rhyniophyte">rhyniophytes</a>", but is not present in any living plants.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2015)">citation needed</span></a></i>]</sup></li></ul> <p>The other three terms are used where there is more than one strand of primary xylem. </p> <ul><li><i>Exarch</i> is used when there is more than one strand of primary xylem in a stem or root, and the xylem develops from the outside inwards towards the center, i.e., centripetally. The metaxylem is thus closest to the center of the stem or root, and the protoxylem is closest to the periphery. The roots of <a href="/wiki/Vascular_plant" title="Vascular plant">vascular plants</a> are generally considered to have exarch development.<sup id="cite_ref-FosterGifford1974_43-1" class="reference"><a href="#cite_note-FosterGifford1974-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup></li> <li><i>Endarch</i> is used when there is more than one strand of primary xylem in a stem or root, and the xylem develops from the inside outwards towards the periphery, i.e., centrifugally. The protoxylem is thus closest to the center of the stem or root, and the metaxylem is closest to the periphery. The stems of <a href="/wiki/Seed_plant" title="Seed plant">seed plants</a> typically have endarch development.<sup id="cite_ref-FosterGifford1974_43-2" class="reference"><a href="#cite_note-FosterGifford1974-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup></li> <li><i>Mesarch</i> is used when there is more than one strand of primary xylem in a stem or root, and the xylem develops from the middle of a strand in both directions. The metaxylem is thus on both the peripheral and central sides of the strand, with the protoxylem between the metaxylem (possibly surrounded by it). The leaves and stems of many <a href="/wiki/Fern" title="Fern">ferns</a> have mesarch development.<sup id="cite_ref-FosterGifford1974_43-3" class="reference"><a href="#cite_note-FosterGifford1974-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=10" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In his book <i>De plantis libri XVI</i> (On Plants, in 16 books) (1583), the Italian physician and botanist <a href="/wiki/Andrea_Cesalpino" title="Andrea Cesalpino">Andrea Cesalpino</a> proposed that plants draw water from soil not by magnetism (<i>ut magnes ferrum trahit</i>, as magnetic iron attracts) nor by suction (<i>vacuum</i>), but by absorption, as occurs in the case of linen, sponges, or powders.<sup id="cite_ref-46" class="reference"><a href="#cite_note-46"><span class="cite-bracket">[</span>46<span class="cite-bracket">]</span></a></sup> The Italian biologist <a href="/wiki/Marcello_Malpighi" title="Marcello Malpighi">Marcello Malpighi</a> was the first person to describe and illustrate xylem vessels, which he did in his book <i>Anatome plantarum</i> ... (1675).<sup id="cite_ref-47" class="reference"><a href="#cite_note-47"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-48" class="reference"><a href="#cite_note-48"><span class="cite-bracket">[</span>note 1<span class="cite-bracket">]</span></a></sup> Although Malpighi believed that xylem contained only air, the British physician and botanist <a href="/wiki/Nehemiah_Grew" title="Nehemiah Grew">Nehemiah Grew</a>, who was Malpighi's contemporary, believed that sap ascended both through the bark and through the xylem.<sup id="cite_ref-49" class="reference"><a href="#cite_note-49"><span class="cite-bracket">[</span>48<span class="cite-bracket">]</span></a></sup> However, according to Grew, <a href="/wiki/Capillary_action" title="Capillary action">capillary action</a> in the xylem would raise the sap by only a few inches; to raise the sap to the top of a tree, Grew proposed that the parenchymal cells become turgid and thereby not only squeeze the sap in the tracheids but force some sap from the parenchyma into the tracheids.<sup id="cite_ref-50" class="reference"><a href="#cite_note-50"><span class="cite-bracket">[</span>49<span class="cite-bracket">]</span></a></sup> In 1727, English clergyman and botanist <a href="/wiki/Stephen_Hales" title="Stephen Hales">Stephen Hales</a> showed that transpiration by a plant's leaves causes water to move through its xylem.<sup id="cite_ref-51" class="reference"><a href="#cite_note-51"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-52" class="reference"><a href="#cite_note-52"><span class="cite-bracket">[</span>note 2<span class="cite-bracket">]</span></a></sup> By 1891, the Polish-German botanist <a href="/wiki/Eduard_Strasburger" title="Eduard Strasburger">Eduard Strasburger</a> had shown that the transport of water in plants did not require the xylem cells to be alive.<sup id="cite_ref-53" class="reference"><a href="#cite_note-53"><span class="cite-bracket">[</span>51<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=11" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Soil_plant_atmosphere_continuum" class="mw-redirect" title="Soil plant atmosphere continuum">Soil plant atmosphere continuum</a></li> <li><a href="/wiki/Suction" title="Suction">Suction</a></li> <li><a href="/wiki/Tylosis_(Botany)" class="mw-redirect" title="Tylosis (Botany)">Tylosis</a></li> <li><a href="/wiki/Vascular_tissue" title="Vascular tissue">Vascular tissue</a></li> <li><a href="/wiki/Xylem_sap" class="mw-redirect" title="Xylem sap">Xylem sap</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Explanatory_notes">Explanatory notes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=12" title="Edit section: Explanatory notes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-48"><span class="mw-cite-backlink"><b><a href="#cite_ref-48">^</a></b></span> <span class="reference-text">Malpighi first described xylem vessels and named tracheid cells. From p. 8 of (Malpighi, 1675): <i>" ... haec tubulosa sunt & subrotunda, identidem tamen angustantur, & perpetuo patent, nullumque, ut observare potui, effundunt humorem: Argentea lamina L, in spiram contorta, componuntur, ut facile laceratione, (velut in bombycinis tracheis expertus sum,) in hanc oblongam & continuatam fasciam resolvantur. Lamina haec, si ulterius microscopio lustretur, particulis squamatim componitur; quod etiam in tracheis insectorum deprehenditur. Spiralibus hisce vasculis, seu ut verius loquar, tracheis, ligneae fibrae M adstant, quae secundum longitudinem productae, ad majorem firmitudinem & robur, transversalium utriculorum ordines N superequitant, ita ut fiat veluti storea."</i> ( ... these [vessels] are tubular and somewhat round, yet often become narrow, and they are always open, and none, as [far as] I could perceive, exude a liquid: they are composed of silvery sheets <i>L</i>, twisted into a helix, although they can easily be unbound, by tearing, into this somewhat long and connected strip (just as I have done in silkworm treacheas). This sheet, if it be examined further with a microscope, is composed of scale-like particles; which likewise is observed in the tracheas of insects. On these helical vessels, or as I will more rightly say, "tracheas", there stand woody filaments <i>M</i>, which being extended in length straddle – for greater strength and hardness – lines of transverse cells <i>N</i>, so that it is constructed like a mat.)</span> </li> <li id="cite_note-52"><span class="mw-cite-backlink"><b><a href="#cite_ref-52">^</a></b></span> <span class="reference-text">Hales explained that although capillary action might help raise water within the xylem, transpiration caused water to actually move through the xylem. From (Hales, 1727), p. 100: "And by the same [capillary] principle it is, that we see in the preceding Experiments plants imbibe moisture so vigorously up their fine capillary vessels; which moisture, as it is carried off in perspiration [i.e., transpiration], (by the action of warmth), thereby gives the sap vessels liberty to be almost continually attracting fresh supplies, which they could not do, if they were fully saturate with moisture: For without perspiration the sap must necessarily stagnate, not withstanding the sap vessels are so curiously adapted by their exceeding fineness, to raise the sap to great heights, in reciprocal proportion to their very minute diameters."</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=13" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Citations">Citations</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=14" title="Edit section: Citations"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626" /><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFPurcell" class="citation web cs1">Purcell, Adam. <a rel="nofollow" class="external text" href="https://www.basicbiology.net/plants/physiology/xylem-phloem/">"Xylem and phloem"</a>. <i>Basic Biology</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160504195130/https://www.basicbiology.net/plants/physiology/xylem-phloem/">Archived</a> from the original on 2016-05-04.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Basic+Biology&rft.atitle=Xylem+and+phloem&rft.aulast=Purcell&rft.aufirst=Adam&rft_id=https%3A%2F%2Fwww.basicbiology.net%2Fplants%2Fphysiology%2Fxylem-phloem%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKeith_Roberts2007" class="citation book cs1">Keith Roberts, ed. (2007). <i>Handbook of Plant Science</i>. Vol. 1 (Illustrated ed.). <a href="/wiki/Wiley_(publisher)" title="Wiley (publisher)">John Wiley & Sons</a>. p. 185. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780470057230" title="Special:BookSources/9780470057230"><bdi>9780470057230</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Handbook+of+Plant+Science&rft.pages=185&rft.edition=Illustrated&rft.pub=John+Wiley+%26+Sons&rft.date=2007&rft.isbn=9780470057230&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFRichard_B._Mancke1977" class="citation book cs1">Richard B. Mancke (1977). <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://archive.org/details/providingforener00twen"><i>Providing for Energy: Report of the Twentieth Century Fund Task Force on United States Energy Policy</i></a></span> (illustrated ed.). Tata McGraw-Hill Education. p. <a rel="nofollow" class="external text" href="https://archive.org/details/providingforener00twen/page/42">42</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780070656178" title="Special:BookSources/9780070656178"><bdi>9780070656178</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Providing+for+Energy%3A+Report+of+the+Twentieth+Century+Fund+Task+Force+on+United+States+Energy+Policy&rft.pages=42&rft.edition=illustrated&rft.pub=Tata+McGraw-Hill+Education&rft.date=1977&rft.isbn=9780070656178&rft.au=Richard+B.+Mancke&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fprovidingforener00twen&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFNägeli1858" class="citation journal cs1 cs1-prop-foreign-lang-source">Nägeli, Carl (1858). <a rel="nofollow" class="external text" href="https://www.biodiversitylibrary.org/item/91249#page/5/mode/1up">"Das Wachstum des Stammes und der Wurzel bei den Gefäßpflanzen und die Anordnung der Gefäßstränge im Stengel"</a> [The growth of the stem and of the root among vascular plants and the arrangement of the vascular strands in the stalk]. <i>Beiträge zur Wissenschaftlichen Botanik (Contributions to Scientific Botany)</i> (in German). <b>1</b>: <span class="nowrap">1–</span>156.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Beitr%C3%A4ge+zur+Wissenschaftlichen+Botanik+%28Contributions+to+Scientific+Botany%29&rft.atitle=Das+Wachstum+des+Stammes+und+der+Wurzel+bei+den+Gef%C3%A4%C3%9Fpflanzen+und+die+Anordnung+der+Gef%C3%A4%C3%9Fstr%C3%A4nge+im+Stengel&rft.volume=1&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1-%3C%2Fspan%3E156&rft.date=1858&rft.aulast=N%C3%A4geli&rft.aufirst=Carl&rft_id=https%3A%2F%2Fwww.biodiversitylibrary.org%2Fitem%2F91249%23page%2F5%2Fmode%2F1up&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span> From p. 9: <i>"Ich will die beiden welche von dem Cambium nach aussen und nach innen gebildet werden, Phloëm und Xylem nennen."</i> (I will call the two parts of the permanent tissue, which are formed by the cambium outwardly and inwardly, "phloëm" and "xylem".)</span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFBuvat1989" class="citation book cs1">Buvat, Roger (1989). "Phloem". <i>Ontogeny, Cell Differentiation, and Structure of Vascular Plants</i>. pp. <span class="nowrap">287–</span>368. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-642-73635-3_10">10.1007/978-3-642-73635-3_10</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-642-73637-7" title="Special:BookSources/978-3-642-73637-7"><bdi>978-3-642-73637-7</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Phloem&rft.btitle=Ontogeny%2C+Cell+Differentiation%2C+and+Structure+of+Vascular+Plants&rft.pages=%3Cspan+class%3D%22nowrap%22%3E287-%3C%2Fspan%3E368&rft.date=1989&rft_id=info%3Adoi%2F10.1007%2F978-3-642-73635-3_10&rft.isbn=978-3-642-73637-7&rft.aulast=Buvat&rft.aufirst=Roger&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFRaven,_Peter_A.Evert,_Ray_F.Eichhorn,_Susan_E.1999" class="citation book cs1">Raven, Peter A.; Evert, Ray F.; Eichhorn, Susan E. (1999). <i>Biology of Plants</i>. W.H. Freeman and Company. pp. <span class="nowrap">576–</span>577. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-57259-611-5" title="Special:BookSources/978-1-57259-611-5"><bdi>978-1-57259-611-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Biology+of+Plants&rft.pages=%3Cspan+class%3D%22nowrap%22%3E576-%3C%2Fspan%3E577&rft.pub=W.H.+Freeman+and+Company&rft.date=1999&rft.isbn=978-1-57259-611-5&rft.au=Raven%2C+Peter+A.&rft.au=Evert%2C+Ray+F.&rft.au=Eichhorn%2C+Susan+E.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.britannica.com/EBchecked/topic/650951/xylem">Xylem</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20110916145301/http://www.britannica.com/EBchecked/topic/650951/xylem">Archived</a> 2011-09-16 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>. Encyclopædia Britannica</span> </li> <li id="cite_note-mcculloh-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-mcculloh_8-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFMcCullohJohn_S._SperryFrederick_R._Adler2003" class="citation journal cs1">McCulloh, Katherine A.; John S. Sperry; Frederick R. Adler (2003). "Water transport in plants obeys Murray's law". <i>Nature</i>. <b>421</b> (6926): <span class="nowrap">939–</span>942. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2003Natur.421..939M">2003Natur.421..939M</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fnature01444">10.1038/nature01444</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/12607000">12607000</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:4395034">4395034</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Water+transport+in+plants+obeys+Murray%27s+law&rft.volume=421&rft.issue=6926&rft.pages=%3Cspan+class%3D%22nowrap%22%3E939-%3C%2Fspan%3E942&rft.date=2003&rft_id=info%3Adoi%2F10.1038%2Fnature01444&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A4395034%23id-name%3DS2CID&rft_id=info%3Apmid%2F12607000&rft_id=info%3Abibcode%2F2003Natur.421..939M&rft.aulast=McCulloh&rft.aufirst=Katherine+A.&rft.au=John+S.+Sperry&rft.au=Frederick+R.+Adler&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Judd-9"><span class="mw-cite-backlink">^ <a href="#cite_ref-Judd_9-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Judd_9-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFWalter_S._Judd2002" class="citation book cs1">Walter S. Judd (2002). Walter S. Judd (ed.). <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://archive.org/details/plantsystematics0002unse"><i>Plant systematics: A phylogenetic approach</i></a></span> (2 ed.). W.H. Freeman. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-87893-403-0" title="Special:BookSources/0-87893-403-0"><bdi>0-87893-403-0</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Plant+systematics%3A+A+phylogenetic+approach&rft.edition=2&rft.pub=W.H.+Freeman&rft.date=2002&rft.isbn=0-87893-403-0&rft.au=Walter+S.+Judd&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fplantsystematics0002unse&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFDickison,_W.C.2000" class="citation book cs1">Dickison, W.C. (2000). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=-os1kvkFbS0C"><i>Integrative Plant Anatomy (page 196)</i></a>. Elsevier Science. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780080508917" title="Special:BookSources/9780080508917"><bdi>9780080508917</bdi></a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20171106151303/https://books.google.com/books?id=-os1kvkFbS0C">Archived</a> from the original on 2017-11-06.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Integrative+Plant+Anatomy+%28page+196%29&rft.pub=Elsevier+Science&rft.date=2000&rft.isbn=9780080508917&rft.au=Dickison%2C+W.C.&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3D-os1kvkFbS0C&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKochSillettJenningsDavis2004" class="citation journal cs1">Koch, George W.; Sillett, Stephen C.; Jennings, Gregory M.; Davis, Stephen D. (2004). "The limits to tree height". <i>Nature</i>. <b>428</b> (6985): <span class="nowrap">851–</span>854. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2004Natur.428..851K">2004Natur.428..851K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fnature02417">10.1038/nature02417</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/15103376">15103376</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:11846291">11846291</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=The+limits+to+tree+height&rft.volume=428&rft.issue=6985&rft.pages=%3Cspan+class%3D%22nowrap%22%3E851-%3C%2Fspan%3E854&rft.date=2004&rft_id=info%3Adoi%2F10.1038%2Fnature02417&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A11846291%23id-name%3DS2CID&rft_id=info%3Apmid%2F15103376&rft_id=info%3Abibcode%2F2004Natur.428..851K&rft.aulast=Koch&rft.aufirst=George+W.&rft.au=Sillett%2C+Stephen+C.&rft.au=Jennings%2C+Gregory+M.&rft.au=Davis%2C+Stephen+D.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKnoblauchKnoblauchMullendoreSavage2016" class="citation journal cs1">Knoblauch, Michael; Knoblauch, Jan; Mullendore, Daniel L.; Savage, Jessica A.; Babst, Benjamin A.; Beecher, Sierra D.; Dodgen, Adam C.; Jensen, Kaare H.; Holbrook, N. Michele (2016-06-02). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4946904">"Testing the Münch hypothesis of long distance phloem transport in plants"</a>. <i>eLife</i>. <b>5</b>: e15341. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.7554%2FeLife.15341">10.7554/eLife.15341</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/2050-084X">2050-084X</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4946904">4946904</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/27253062">27253062</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=eLife&rft.atitle=Testing+the+M%C3%BCnch+hypothesis+of+long+distance+phloem+transport+in+plants&rft.volume=5&rft.pages=e15341&rft.date=2016-06-02&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4946904%23id-name%3DPMC&rft.issn=2050-084X&rft_id=info%3Apmid%2F27253062&rft_id=info%3Adoi%2F10.7554%2FeLife.15341&rft.aulast=Knoblauch&rft.aufirst=Michael&rft.au=Knoblauch%2C+Jan&rft.au=Mullendore%2C+Daniel+L.&rft.au=Savage%2C+Jessica+A.&rft.au=Babst%2C+Benjamin+A.&rft.au=Beecher%2C+Sierra+D.&rft.au=Dodgen%2C+Adam+C.&rft.au=Jensen%2C+Kaare+H.&rft.au=Holbrook%2C+N.+Michele&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4946904&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFTim_J._TibbettsFrank_W._Ewers2000" class="citation journal cs1">Tim J. Tibbetts; Frank W. Ewers (2000). <a rel="nofollow" class="external text" href="https://doi.org/10.2307%2F2656720">"Root pressure and specific conductivity in temperate lianas: exotic <i>Celastrus orbiculatus</i> (Celastraceae) vs. Native <i>Vitis riparia</i> (Vitaceae)"</a>. <i>American Journal of Botany</i>. <b>87</b> (9): <span class="nowrap">1272–</span>78. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.2307%2F2656720">10.2307/2656720</a></span>. <a href="/wiki/JSTOR_(identifier)" class="mw-redirect" title="JSTOR (identifier)">JSTOR</a> <a rel="nofollow" class="external text" href="https://www.jstor.org/stable/2656720">2656720</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/10991898">10991898</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=American+Journal+of+Botany&rft.atitle=Root+pressure+and+specific+conductivity+in+temperate+lianas%3A+exotic+Celastrus+orbiculatus+%28Celastraceae%29+vs.+Native+Vitis+riparia+%28Vitaceae%29&rft.volume=87&rft.issue=9&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1272-%3C%2Fspan%3E78&rft.date=2000&rft_id=info%3Apmid%2F10991898&rft_id=https%3A%2F%2Fwww.jstor.org%2Fstable%2F2656720%23id-name%3DJSTOR&rft_id=info%3Adoi%2F10.2307%2F2656720&rft.au=Tim+J.+Tibbetts&rft.au=Frank+W.+Ewers&rft_id=https%3A%2F%2Fdoi.org%2F10.2307%252F2656720&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text">Cruiziat, Pierre and Richter, Hanno. <a rel="nofollow" class="external text" href="http://4e.plantphys.net/article.php?ch=&id=99">Plant Physiology</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20081228144231/http://4e.plantphys.net/article.php?ch=&id=99">Archived</a> 2008-12-28 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>. Sinauer Associates.</span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFAnthony_R._YeoTimothy_J._Flowers2007" class="citation book cs1">Anthony R. Yeo; Timothy J. Flowers, eds. (2007). <span class="id-lock-limited" title="Free access subject to limited trial, subscription normally required"><a rel="nofollow" class="external text" href="https://archive.org/details/plantsolutetrans00yeoa"><i>Plant solute transport</i></a></span>. Oxford UK: Blackwell Publishing. p. <a rel="nofollow" class="external text" href="https://archive.org/details/plantsolutetrans00yeoa/page/n240">221</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-4051-3995-3" title="Special:BookSources/978-1-4051-3995-3"><bdi>978-1-4051-3995-3</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Plant+solute+transport&rft.place=Oxford+UK&rft.pages=221&rft.pub=Blackwell+Publishing&rft.date=2007&rft.isbn=978-1-4051-3995-3&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fplantsolutetrans00yeoa&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Nardini2011-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-Nardini2011_16-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFNardiniLo_GulloSalleo2011" class="citation journal cs1">Nardini, Andrea; Lo Gullo, Maria A.; Salleo, Sebastiano (2011). "Refilling embolized xylem conduits: Is it a matter of phloem unloading?". <i>Plant Science</i>. <b>180</b> (4): <span class="nowrap">604–</span>611. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2011PlnSc.180..604N">2011PlnSc.180..604N</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.plantsci.2010.12.011">10.1016/j.plantsci.2010.12.011</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0168-9452">0168-9452</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/21421408">21421408</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Plant+Science&rft.atitle=Refilling+embolized+xylem+conduits%3A+Is+it+a+matter+of+phloem+unloading%3F&rft.volume=180&rft.issue=4&rft.pages=%3Cspan+class%3D%22nowrap%22%3E604-%3C%2Fspan%3E611&rft.date=2011&rft_id=info%3Adoi%2F10.1016%2Fj.plantsci.2010.12.011&rft.issn=0168-9452&rft_id=info%3Apmid%2F21421408&rft_id=info%3Abibcode%2F2011PlnSc.180..604N&rft.aulast=Nardini&rft.aufirst=Andrea&rft.au=Lo+Gullo%2C+Maria+A.&rft.au=Salleo%2C+Sebastiano&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFDixonJoly1894" class="citation journal cs1">Dixon, Henry H.; Joly, J. (1894). <a rel="nofollow" class="external text" href="https://babel.hathitrust.org/cgi/pt?id=mdp.39015001235830;view=1up;seq=566">"On the ascent of sap"</a>. <i>Annals of Botany</i>. <b>8</b>: <span class="nowrap">468–</span>470.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Annals+of+Botany&rft.atitle=On+the+ascent+of+sap&rft.volume=8&rft.pages=%3Cspan+class%3D%22nowrap%22%3E468-%3C%2Fspan%3E470&rft.date=1894&rft.aulast=Dixon&rft.aufirst=Henry+H.&rft.au=Joly%2C+J.&rft_id=https%3A%2F%2Fbabel.hathitrust.org%2Fcgi%2Fpt%3Fid%3Dmdp.39015001235830%3Bview%3D1up%3Bseq%3D566&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFDixonJoly1895" class="citation journal cs1">Dixon, Henry H.; Joly, J. (1895). <a rel="nofollow" class="external text" href="https://babel.hathitrust.org/cgi/pt?id=uva.x001659730;view=1up;seq=609">"On the ascent of sap"</a>. <i>Philosophical Transactions of the Royal Society of London, Series B</i>. <b>186</b>: <span class="nowrap">563–</span>576. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1098%2Frstb.1895.0012">10.1098/rstb.1895.0012</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Philosophical+Transactions+of+the+Royal+Society+of+London%2C+Series+B&rft.atitle=On+the+ascent+of+sap&rft.volume=186&rft.pages=%3Cspan+class%3D%22nowrap%22%3E563-%3C%2Fspan%3E576&rft.date=1895&rft_id=info%3Adoi%2F10.1098%2Frstb.1895.0012&rft.aulast=Dixon&rft.aufirst=Henry+H.&rft.au=Joly%2C+J.&rft_id=https%3A%2F%2Fbabel.hathitrust.org%2Fcgi%2Fpt%3Fid%3Duva.x001659730%3Bview%3D1up%3Bseq%3D609&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFTyree,_M.T.1997" class="citation journal cs1">Tyree, M.T. (1997). <a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fjxb%2F48.10.1753">"The Cohesion-Tension theory of sap ascent: current controversies"</a>. <i>Journal of Experimental Botany</i>. <b>48</b> (10): <span class="nowrap">1753–</span>1765. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fjxb%2F48.10.1753">10.1093/jxb/48.10.1753</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Experimental+Botany&rft.atitle=The+Cohesion-Tension+theory+of+sap+ascent%3A+current+controversies&rft.volume=48&rft.issue=10&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1753-%3C%2Fspan%3E1765&rft.date=1997&rft_id=info%3Adoi%2F10.1093%2Fjxb%2F48.10.1753&rft.au=Tyree%2C+M.T.&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fjxb%252F48.10.1753&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFWang,_Z.Chang,_C.-C.Hong,_S.-J.Sheng,_Y.-J.2012" class="citation journal cs1">Wang, Z.; Chang, C.-C.; Hong, S.-J.; Sheng, Y.-J.; Tsao, H.-K. (2012). "Capillary Rise in a Microchannel of Arbitrary Shape and Wettability: Hysteresis Loop". <i>Langmuir</i>. <b>28</b> (49): <span class="nowrap">16917–</span>16926. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Fla3036242">10.1021/la3036242</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/23171321">23171321</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Langmuir&rft.atitle=Capillary+Rise+in+a+Microchannel+of+Arbitrary+Shape+and+Wettability%3A+Hysteresis+Loop&rft.volume=28&rft.issue=49&rft.pages=%3Cspan+class%3D%22nowrap%22%3E16917-%3C%2Fspan%3E16926&rft.date=2012&rft_id=info%3Adoi%2F10.1021%2Fla3036242&rft_id=info%3Apmid%2F23171321&rft.au=Wang%2C+Z.&rft.au=Chang%2C+C.-C.&rft.au=Hong%2C+S.-J.&rft.au=Sheng%2C+Y.-J.&rft.au=Tsao%2C+H.-K.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFAskenasy1895" class="citation journal cs1 cs1-prop-foreign-lang-source">Askenasy, E. (1895). <a rel="nofollow" class="external text" href="https://babel.hathitrust.org/cgi/pt?id=uc1.c079536710;view=1up;seq=269">"Ueber das Saftsteigen"</a> [On the ascent of sap]. <i>Botanisches Centralblatt</i> (in German). <b>62</b>: <span class="nowrap">237–</span>238.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Botanisches+Centralblatt&rft.atitle=Ueber+das+Saftsteigen&rft.volume=62&rft.pages=%3Cspan+class%3D%22nowrap%22%3E237-%3C%2Fspan%3E238&rft.date=1895&rft.aulast=Askenasy&rft.aufirst=E.&rft_id=https%3A%2F%2Fbabel.hathitrust.org%2Fcgi%2Fpt%3Fid%3Duc1.c079536710%3Bview%3D1up%3Bseq%3D269&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFAskenasy1895" class="citation journal cs1 cs1-prop-foreign-lang-source">Askenasy, E. (1895). <a rel="nofollow" class="external text" href="https://www.biodiversitylibrary.org/item/43534#page/349/mode/1up">"Ueber das Saftsteigen"</a> [On the ascent of sap]. <i>Verhandlungen des Naturhistorisch-medizinischen Vereins zu Heidelberg (Proceedings of the Natural History-Medical Society at Heidelberg)</i>. 2nd series (in German). <b>5</b>: <span class="nowrap">325–</span>345.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Verhandlungen+des+Naturhistorisch-medizinischen+Vereins+zu+Heidelberg+%28Proceedings+of+the+Natural+History-Medical+Society+at+Heidelberg%29&rft.atitle=Ueber+das+Saftsteigen&rft.volume=5&rft.pages=%3Cspan+class%3D%22nowrap%22%3E325-%3C%2Fspan%3E345&rft.date=1895&rft.aulast=Askenasy&rft.aufirst=E.&rft_id=https%3A%2F%2Fwww.biodiversitylibrary.org%2Fitem%2F43534%23page%2F349%2Fmode%2F1up&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFDixon1914" class="citation book cs1">Dixon, H (1914). <a rel="nofollow" class="external text" href="https://archive.org/stream/transpirationasc00dixo#page/n5"><i>Transpiration and the ascent of sap in plants</i></a>. London, England, UK: Macmillan and Co.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Transpiration+and+the+ascent+of+sap+in+plants&rft.place=London%2C+England%2C+UK&rft.pub=Macmillan+and+Co.&rft.date=1914&rft.aulast=Dixon&rft.aufirst=H&rft_id=https%3A%2F%2Farchive.org%2Fstream%2Ftranspirationasc00dixo%23page%2Fn5&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFDixon1924" class="citation book cs1">Dixon, H (1924). <i>The transpiration stream</i>. London: University of London Press, Ltd. p. 80.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+transpiration+stream&rft.place=London&rft.pages=80&rft.pub=University+of+London+Press%2C+Ltd&rft.date=1924&rft.aulast=Dixon&rft.aufirst=H&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCampbell2002" class="citation book cs1">Campbell, Neil (2002). <a rel="nofollow" class="external text" href="https://archive.org/details/biologyc00camp/page/759"><i>Biology</i></a>. San Francisco, CA: Pearson Education, Inc. pp. <a rel="nofollow" class="external text" href="https://archive.org/details/biologyc00camp/page/759">759</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-8053-6624-2" title="Special:BookSources/978-0-8053-6624-2"><bdi>978-0-8053-6624-2</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Biology&rft.place=San+Francisco%2C+CA&rft.pages=759&rft.pub=Pearson+Education%2C+Inc.&rft.date=2002&rft.isbn=978-0-8053-6624-2&rft.aulast=Campbell&rft.aufirst=Neil&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fbiologyc00camp%2Fpage%2F759&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFZimmerman2002" class="citation journal cs1">Zimmerman, Ulrich (2002). "What are the driving forces for water lifting in the xylem conduit?". <i>Physiologia Plantarum</i>. <b>114</b> (3): <span class="nowrap">327–</span>335. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2002PPlan.114..327Z">2002PPlan.114..327Z</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1034%2Fj.1399-3054.2002.1140301.x">10.1034/j.1399-3054.2002.1140301.x</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/12060254">12060254</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Physiologia+Plantarum&rft.atitle=What+are+the+driving+forces+for+water+lifting+in+the+xylem+conduit%3F&rft.volume=114&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3E327-%3C%2Fspan%3E335&rft.date=2002&rft_id=info%3Apmid%2F12060254&rft_id=info%3Adoi%2F10.1034%2Fj.1399-3054.2002.1140301.x&rft_id=info%3Abibcode%2F2002PPlan.114..327Z&rft.aulast=Zimmerman&rft.aufirst=Ulrich&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-tyree1997-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-tyree1997_27-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFTyree1997" class="citation journal cs1">Tyree, Melvin T. (1997). <a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fjxb%2F48.10.1753">"The cohesion-tension theory of sap ascent: current controversies"</a>. <i>Journal of Experimental Botany</i>. <b>48</b> (10): <span class="nowrap">1753–</span>1765. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fjxb%2F48.10.1753">10.1093/jxb/48.10.1753</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Experimental+Botany&rft.atitle=The+cohesion-tension+theory+of+sap+ascent%3A+current+controversies&rft.volume=48&rft.issue=10&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1753-%3C%2Fspan%3E1765&rft.date=1997&rft_id=info%3Adoi%2F10.1093%2Fjxb%2F48.10.1753&rft.aulast=Tyree&rft.aufirst=Melvin+T.&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fjxb%252F48.10.1753&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20090918110039/http://bugs.bio.usyd.edu.au/learning/resources/plant_form_function/external_sites/PAP/Lab08_WaterPot/08Lab_14.html">The pressure of the water potential of the xylem in your plant's stem can be determined with the Scholander bomb.</a> bio.usyd.edu.au</span> </li> <li id="cite_note-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-29">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFAndrew_J._McElrone,_Brendan_Choat,_Greg_A._Gambetta,_Craig_R._Brodersen2013" class="citation web cs1">Andrew J. McElrone, Brendan Choat, Greg A. Gambetta, Craig R. Brodersen (2013). <a rel="nofollow" class="external text" href="https://www.nature.com/scitable/knowledge/library/water-uptake-and-transport-in-vascular-plants-103016037">"Water Uptake and Transport in Vascular Plants"</a>. <i>The Nature Education Knowledge Project</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=The+Nature+Education+Knowledge+Project&rft.atitle=Water+Uptake+and+Transport+in+Vascular+Plants&rft.date=2013&rft.au=Andrew+J.+McElrone%2C+Brendan+Choat%2C+Greg+A.+Gambetta%2C+Craig+R.+Brodersen&rft_id=https%3A%2F%2Fwww.nature.com%2Fscitable%2Fknowledge%2Flibrary%2Fwater-uptake-and-transport-in-vascular-plants-103016037&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_web" title="Template:Cite web">cite web</a>}}</code>: CS1 maint: multiple names: authors list (<a href="/wiki/Category:CS1_maint:_multiple_names:_authors_list" title="Category:CS1 maint: multiple names: authors list">link</a>)</span></span> </li> <li id="cite_note-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-30">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1 cs1-prop-foreign-lang-source"><a rel="nofollow" class="external text" href="https://regi.tankonyvtar.hu/hu/tartalom/tamop412A/2011-0073_structure_of_plants_fungi/ch04s04.html">"Structure of Plants and Fungi|Digitális Tankönyvtár"</a>. <i>regi.tankonyvtar.hu</i> (in Hungarian)<span class="reference-accessdate">. Retrieved <span class="nowrap">2021-04-02</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=regi.tankonyvtar.hu&rft.atitle=Structure+of+Plants+and+Fungi%7CDigit%C3%A1lis+Tank%C3%B6nyvt%C3%A1r&rft_id=https%3A%2F%2Fregi.tankonyvtar.hu%2Fhu%2Ftartalom%2Ftamop412A%2F2011-0073_structure_of_plants_fungi%2Fch04s04.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span><sup class="noprint Inline-Template"><span style="white-space: nowrap;">[<i><a href="/wiki/Wikipedia:Link_rot" title="Wikipedia:Link rot"><span title=" Dead link tagged October 2023">permanent dead link</span></a></i><span style="visibility:hidden; color:transparent; padding-left:2px">‍</span>]</span></sup></span> </li> <li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-31">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCarlquist,_S.E.L._Schneider2002" class="citation journal cs1">Carlquist, S.; E.L. Schneider (2002). "The tracheid–vessel element transition in angiosperms involves multiple independent features: cladistic consequences". <i>American Journal of Botany</i>. <b>89</b> (2): <span class="nowrap">185–</span>195. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.3732%2Fajb.89.2.185">10.3732/ajb.89.2.185</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/21669726">21669726</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=American+Journal+of+Botany&rft.atitle=The+tracheid%E2%80%93vessel+element+transition+in+angiosperms+involves+multiple+independent+features%3A+cladistic+consequences&rft.volume=89&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E185-%3C%2Fspan%3E195&rft.date=2002&rft_id=info%3Adoi%2F10.3732%2Fajb.89.2.185&rft_id=info%3Apmid%2F21669726&rft.au=Carlquist%2C+S.&rft.au=E.L.+Schneider&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-32">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCronquist,_A.1988" class="citation book cs1">Cronquist, A. (August 1988). <i>The Evolution and Classification of Flowering Plants</i>. New York, New York: New York Botanical Garden Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-89327-332-3" title="Special:BookSources/978-0-89327-332-3"><bdi>978-0-89327-332-3</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Evolution+and+Classification+of+Flowering+Plants&rft.place=New+York%2C+New+York&rft.pub=New+York+Botanical+Garden+Press&rft.date=1988-08&rft.isbn=978-0-89327-332-3&rft.au=Cronquist%2C+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Sperry2003-33"><span class="mw-cite-backlink">^ <a href="#cite_ref-Sperry2003_33-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-6"><sup><i><b>g</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-7"><sup><i><b>h</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-8"><sup><i><b>i</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-9"><sup><i><b>j</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-10"><sup><i><b>k</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-11"><sup><i><b>l</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-12"><sup><i><b>m</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-13"><sup><i><b>n</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-14"><sup><i><b>o</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-15"><sup><i><b>p</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-16"><sup><i><b>q</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-17"><sup><i><b>r</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-18"><sup><i><b>s</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-19"><sup><i><b>t</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-20"><sup><i><b>u</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-21"><sup><i><b>v</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-22"><sup><i><b>w</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-23"><sup><i><b>x</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-24"><sup><i><b>y</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-25"><sup><i><b>z</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-26"><sup><i><b>aa</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-27"><sup><i><b>ab</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-28"><sup><i><b>ac</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-29"><sup><i><b>ad</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-30"><sup><i><b>ae</b></i></sup></a> <a href="#cite_ref-Sperry2003_33-31"><sup><i><b>af</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFSperry2003" class="citation journal cs1">Sperry, J. S. (2003). "Evolution of Water Transport and Xylem Structure". <i>International Journal of Plant Sciences</i>. <b>164</b> (3): <span class="nowrap">S115 –</span> <span class="nowrap">S127</span>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F368398">10.1086/368398</a>. <a href="/wiki/JSTOR_(identifier)" class="mw-redirect" title="JSTOR (identifier)">JSTOR</a> <a rel="nofollow" class="external text" href="https://www.jstor.org/stable/3691719">3691719</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:15314720">15314720</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=International+Journal+of+Plant+Sciences&rft.atitle=Evolution+of+Water+Transport+and+Xylem+Structure&rft.volume=164&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3ES115+-%3C%2Fspan%3E+%3Cspan+class%3D%22nowrap%22%3ES127%3C%2Fspan%3E&rft.date=2003&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A15314720%23id-name%3DS2CID&rft_id=https%3A%2F%2Fwww.jstor.org%2Fstable%2F3691719%23id-name%3DJSTOR&rft_id=info%3Adoi%2F10.1086%2F368398&rft.aulast=Sperry&rft.aufirst=J.+S.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Edwards1992-34"><span class="mw-cite-backlink"><b><a href="#cite_ref-Edwards1992_34-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFEdwardsDaviesAxe1992" class="citation journal cs1">Edwards, D.; Davies, K.L.; Axe, L. (1992). "A vascular conducting strand in the early land plant <i>Cooksonia</i>". <i>Nature</i>. <b>357</b> (6380): <span class="nowrap">683–</span>685. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1992Natur.357..683E">1992Natur.357..683E</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2F357683a0">10.1038/357683a0</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:4264332">4264332</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=A+vascular+conducting+strand+in+the+early+land+plant+Cooksonia&rft.volume=357&rft.issue=6380&rft.pages=%3Cspan+class%3D%22nowrap%22%3E683-%3C%2Fspan%3E685&rft.date=1992&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A4264332%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1038%2F357683a0&rft_id=info%3Abibcode%2F1992Natur.357..683E&rft.aulast=Edwards&rft.aufirst=D.&rft.au=Davies%2C+K.L.&rft.au=Axe%2C+L.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Niklas1983-35"><span class="mw-cite-backlink"><b><a href="#cite_ref-Niklas1983_35-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFNiklasSmocovitis1983" class="citation journal cs1">Niklas, K. J.; Smocovitis, V. (1983). "Evidence for a Conducting Strand in Early Silurian (Llandoverian) Plants: Implications for the Evolution of the Land Plants". <i>Paleobiology</i>. <b>9</b> (2): <span class="nowrap">126–</span>137. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1983Pbio....9..126N">1983Pbio....9..126N</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1017%2FS009483730000751X">10.1017/S009483730000751X</a>. <a href="/wiki/JSTOR_(identifier)" class="mw-redirect" title="JSTOR (identifier)">JSTOR</a> <a rel="nofollow" class="external text" href="https://www.jstor.org/stable/2400461">2400461</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:35550235">35550235</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Paleobiology&rft.atitle=Evidence+for+a+Conducting+Strand+in+Early+Silurian+%28Llandoverian%29+Plants%3A+Implications+for+the+Evolution+of+the+Land+Plants&rft.volume=9&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E126-%3C%2Fspan%3E137&rft.date=1983&rft_id=info%3Adoi%2F10.1017%2FS009483730000751X&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A35550235%23id-name%3DS2CID&rft_id=https%3A%2F%2Fwww.jstor.org%2Fstable%2F2400461%23id-name%3DJSTOR&rft_id=info%3Abibcode%2F1983Pbio....9..126N&rft.aulast=Niklas&rft.aufirst=K.+J.&rft.au=Smocovitis%2C+V.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Niklas1985-36"><span class="mw-cite-backlink">^ <a href="#cite_ref-Niklas1985_36-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Niklas1985_36-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Niklas1985_36-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-Niklas1985_36-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-Niklas1985_36-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-Niklas1985_36-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-Niklas1985_36-6"><sup><i><b>g</b></i></sup></a> <a href="#cite_ref-Niklas1985_36-7"><sup><i><b>h</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFNiklas1985" class="citation journal cs1">Niklas, K. J. (1985). "The Evolution of Tracheid Diameter in Early Vascular Plants and Its Implications on the Hydraulic Conductance of the Primary Xylem Strand". <i>Evolution</i>. <b>39</b> (5): <span class="nowrap">1110–</span>1122. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.2307%2F2408738">10.2307/2408738</a>. <a href="/wiki/JSTOR_(identifier)" class="mw-redirect" title="JSTOR (identifier)">JSTOR</a> <a rel="nofollow" class="external text" href="https://www.jstor.org/stable/2408738">2408738</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/28561493">28561493</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Evolution&rft.atitle=The+Evolution+of+Tracheid+Diameter+in+Early+Vascular+Plants+and+Its+Implications+on+the+Hydraulic+Conductance+of+the+Primary+Xylem+Strand&rft.volume=39&rft.issue=5&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1110-%3C%2Fspan%3E1122&rft.date=1985&rft_id=info%3Apmid%2F28561493&rft_id=https%3A%2F%2Fwww.jstor.org%2Fstable%2F2408738%23id-name%3DJSTOR&rft_id=info%3Adoi%2F10.2307%2F2408738&rft.aulast=Niklas&rft.aufirst=K.+J.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Niklas1980-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-Niklas1980_37-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFNiklasPratt1980" class="citation journal cs1">Niklas, K.; Pratt, L. (1980). "Evidence for lignin-like constituents in Early Silurian (Llandoverian) plant fossils". <i>Science</i>. <b>209</b> (4454): <span class="nowrap">396–</span>397. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1980Sci...209..396N">1980Sci...209..396N</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fscience.209.4454.396">10.1126/science.209.4454.396</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/17747811">17747811</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:46073056">46073056</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Science&rft.atitle=Evidence+for+lignin-like+constituents+in+Early+Silurian+%28Llandoverian%29+plant+fossils&rft.volume=209&rft.issue=4454&rft.pages=%3Cspan+class%3D%22nowrap%22%3E396-%3C%2Fspan%3E397&rft.date=1980&rft_id=info%3Adoi%2F10.1126%2Fscience.209.4454.396&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A46073056%23id-name%3DS2CID&rft_id=info%3Apmid%2F17747811&rft_id=info%3Abibcode%2F1980Sci...209..396N&rft.aulast=Niklas&rft.aufirst=K.&rft.au=Pratt%2C+L.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-Qiu2006-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-Qiu2006_38-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFQiu,_Y.L.Li,_L.Wang,_B.Chen,_Z.2006" class="citation journal cs1">Qiu, Y.L.; Li, L.; Wang, B.; Chen, Z.; Knoop, V.; Groth-malonek, M.; Dombrovska, O.; Lee, J.; Kent, L.; Rest, J.; et al. (2006). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1622854">"The deepest divergences in land plants inferred from phylogenomic evidence"</a>. <i>Proceedings of the National Academy of Sciences</i>. <b>103</b> (42): <span class="nowrap">15511–</span>6. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2006PNAS..10315511Q">2006PNAS..10315511Q</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1073%2Fpnas.0603335103">10.1073/pnas.0603335103</a></span>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1622854">1622854</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/17030812">17030812</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Proceedings+of+the+National+Academy+of+Sciences&rft.atitle=The+deepest+divergences+in+land+plants+inferred+from+phylogenomic+evidence&rft.volume=103&rft.issue=42&rft.pages=%3Cspan+class%3D%22nowrap%22%3E15511-%3C%2Fspan%3E6&rft.date=2006&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC1622854%23id-name%3DPMC&rft_id=info%3Apmid%2F17030812&rft_id=info%3Adoi%2F10.1073%2Fpnas.0603335103&rft_id=info%3Abibcode%2F2006PNAS..10315511Q&rft.au=Qiu%2C+Y.L.&rft.au=Li%2C+L.&rft.au=Wang%2C+B.&rft.au=Chen%2C+Z.&rft.au=Knoop%2C+V.&rft.au=Groth-malonek%2C+M.&rft.au=Dombrovska%2C+O.&rft.au=Lee%2C+J.&rft.au=Kent%2C+L.&rft.au=Rest%2C+J.&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC1622854&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-gk-39"><span class="mw-cite-backlink"><b><a href="#cite_ref-gk_39-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFStewart,_W.N.Rothwell,_G.W.1993" class="citation book cs1">Stewart, W.N.; Rothwell, G.W. (1993). <i>Paleobiology and the evolution of plants</i>. Cambridge University Press.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Paleobiology+and+the+evolution+of+plants&rft.pub=Cambridge+University+Press&rft.date=1993&rft.au=Stewart%2C+W.N.&rft.au=Rothwell%2C+G.W.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-40"><span class="mw-cite-backlink"><b><a href="#cite_ref-40">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKoratkar2016" class="citation web cs1">Koratkar, Sanjay (2016-02-24). <a rel="nofollow" class="external text" href="http://www.biologydiscussion.com/plants/cavitation-and-embolism-in-vascular-plants-with-diagram/22732">"Cavitation and Embolism in Vascular Plants (With Diagram)"</a>. <i>Biology Discussion</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Biology+Discussion&rft.atitle=Cavitation+and+Embolism+in+Vascular+Plants+%28With+Diagram%29&rft.date=2016-02-24&rft.aulast=Koratkar&rft.aufirst=Sanjay&rft_id=http%3A%2F%2Fwww.biologydiscussion.com%2Fplants%2Fcavitation-and-embolism-in-vascular-plants-with-diagram%2F22732&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-41"><span class="mw-cite-backlink"><b><a href="#cite_ref-41">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFJohnsonMcCullohWoodruffMeinzerc2012" class="citation journal cs1">Johnson, Daniel M.; McCulloh, Katherine A.; Woodruff, David R.; Meinzerc, Frederick C. (June 2012). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20210313190658/https://www.fs.fed.us/pnw/pubs/journals/pnw_2012_johnson002.pdf">"Hydraulic safety margins and embolism reversal in stems and leaves: Why are conifers and angiosperms so different?"</a> <span class="cs1-format">(PDF)</span>. <i>Plant Science</i>. <b>195</b>: <span class="nowrap">48–</span>53. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2012PlnSc.195...48J">2012PlnSc.195...48J</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.plantsci.2012.06.010">10.1016/j.plantsci.2012.06.010</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/22920998">22920998</a>. Archived from <a rel="nofollow" class="external text" href="https://www.fs.fed.us/pnw/pubs/journals/pnw_2012_johnson002.pdf">the original</a> <span class="cs1-format">(PDF)</span> on Mar 13, 2021.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Plant+Science&rft.atitle=Hydraulic+safety+margins+and+embolism+reversal+in+stems+and+leaves%3A+Why+are+conifers+and+angiosperms+so+different%3F&rft.volume=195&rft.pages=%3Cspan+class%3D%22nowrap%22%3E48-%3C%2Fspan%3E53&rft.date=2012-06&rft_id=info%3Apmid%2F22920998&rft_id=info%3Adoi%2F10.1016%2Fj.plantsci.2012.06.010&rft_id=info%3Abibcode%2F2012PlnSc.195...48J&rft.aulast=Johnson&rft.aufirst=Daniel+M.&rft.au=McCulloh%2C+Katherine+A.&rft.au=Woodruff%2C+David+R.&rft.au=Meinzerc%2C+Frederick+C.&rft_id=https%3A%2F%2Fwww.fs.fed.us%2Fpnw%2Fpubs%2Fjournals%2Fpnw_2012_johnson002.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-42"><span class="mw-cite-backlink"><b><a href="#cite_ref-42">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFBoudaHuggettPratsWason2022" class="citation journal cs1">Bouda, Martin; Huggett, Brett A.; Prats, Kyra A.; Wason, Jay W.; Wilson, Jonathan P.; Brodersen, Craig R. (2022-11-11). <a rel="nofollow" class="external text" href="https://www.science.org/doi/10.1126/science.add2910">"Hydraulic failure as a primary driver of xylem network evolution in early vascular plants"</a>. <i>Science</i>. <b>378</b> (6620): <span class="nowrap">642–</span>646. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2022Sci...378..642B">2022Sci...378..642B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fscience.add2910">10.1126/science.add2910</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0036-8075">0036-8075</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/36356120">36356120</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:253458196">253458196</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Science&rft.atitle=Hydraulic+failure+as+a+primary+driver+of+xylem+network+evolution+in+early+vascular+plants&rft.volume=378&rft.issue=6620&rft.pages=%3Cspan+class%3D%22nowrap%22%3E642-%3C%2Fspan%3E646&rft.date=2022-11-11&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A253458196%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2022Sci...378..642B&rft.issn=0036-8075&rft_id=info%3Adoi%2F10.1126%2Fscience.add2910&rft_id=info%3Apmid%2F36356120&rft.aulast=Bouda&rft.aufirst=Martin&rft.au=Huggett%2C+Brett+A.&rft.au=Prats%2C+Kyra+A.&rft.au=Wason%2C+Jay+W.&rft.au=Wilson%2C+Jonathan+P.&rft.au=Brodersen%2C+Craig+R.&rft_id=https%3A%2F%2Fwww.science.org%2Fdoi%2F10.1126%2Fscience.add2910&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-FosterGifford1974-43"><span class="mw-cite-backlink">^ <a href="#cite_ref-FosterGifford1974_43-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FosterGifford1974_43-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-FosterGifford1974_43-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-FosterGifford1974_43-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFFosterGifford1974" class="citation book cs1">Foster, A.S.; Gifford, E.M. (1974). <a rel="nofollow" class="external text" href="https://archive.org/details/comparativemorph00fost/page/55"><i>Comparative Morphology of Vascular Plants</i></a> (2nd ed.). San Francisco: W.H. Freeman. pp. <a rel="nofollow" class="external text" href="https://archive.org/details/comparativemorph00fost/page/55">55–56</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-7167-0712-7" title="Special:BookSources/978-0-7167-0712-7"><bdi>978-0-7167-0712-7</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Comparative+Morphology+of+Vascular+Plants&rft.place=San+Francisco&rft.pages=55-56&rft.edition=2nd&rft.pub=W.H.+Freeman&rft.date=1974&rft.isbn=978-0-7167-0712-7&rft.aulast=Foster&rft.aufirst=A.S.&rft.au=Gifford%2C+E.M.&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fcomparativemorph00fost%2Fpage%2F55&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-44"><span class="mw-cite-backlink"><b><a href="#cite_ref-44">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFTaylorTaylorKrings2009" class="citation book cs1">Taylor, T.N.; Taylor, E.L.; Krings, M. (2009). <i>Paleobotany, the Biology and Evolution of Fossil Plants</i> (2nd ed.). Amsterdam; Boston: Academic Press. pp. 207ff., 212ff. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-12-373972-8" title="Special:BookSources/978-0-12-373972-8"><bdi>978-0-12-373972-8</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Paleobotany%2C+the+Biology+and+Evolution+of+Fossil+Plants&rft.place=Amsterdam%3B+Boston&rft.pages=207ff.%2C+212ff&rft.edition=2nd&rft.pub=Academic+Press&rft.date=2009&rft.isbn=978-0-12-373972-8&rft.aulast=Taylor&rft.aufirst=T.N.&rft.au=Taylor%2C+E.L.&rft.au=Krings%2C+M.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-45"><span class="mw-cite-backlink"><b><a href="#cite_ref-45">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFWhiteKazlev" class="citation web cs1">White, A. Toby; Kazlev, M. Alan. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20101220181617/http://palaeos.com/Plants/Lists/Glossary/GlossaryA.html">"Glossary"</a>. <i>palaeos.com</i>. Archived from <a rel="nofollow" class="external text" href="http://www.palaeos.com/Plants/Lists/Glossary/GlossaryA.html">the original</a> on December 20, 2010.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=palaeos.com&rft.atitle=Glossary&rft.aulast=White&rft.aufirst=A.+Toby&rft.au=Kazlev%2C+M.+Alan&rft_id=http%3A%2F%2Fwww.palaeos.com%2FPlants%2FLists%2FGlossary%2FGlossaryA.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-46"><span class="mw-cite-backlink"><b><a href="#cite_ref-46">^</a></b></span> <span class="reference-text">See: <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCesalpino1583" class="citation book cs1 cs1-prop-foreign-lang-source">Cesalpino, Andrea (1583). <a rel="nofollow" class="external text" href="https://archive.org/details/deplantislibrixv00cesa"><i>De Plantis libri XVI</i></a> [<i>On Plants, in 16 books</i>] (in Latin). Florence, Italy: Giorgio Marescotti. p. <a rel="nofollow" class="external text" href="https://archive.org/details/deplantislibrixv00cesa/page/4">4</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=De+Plantis+libri+XVI&rft.place=Florence%2C+Italy&rft.pages=4&rft.pub=Giorgio+Marescotti&rft.date=1583&rft.aulast=Cesalpino&rft.aufirst=Andrea&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fdeplantislibrixv00cesa&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span> From p. 4: <i>"An quædam sicca secundum naturam humorem trahunt? ut lintea, spongiæ, pulveres: ... "</i> (Or [as] dry things attract [i.e., absorb] according to the liquid's nature? [such] as linen, sponges, powders: ... )</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFBellorini2016" class="citation book cs1">Bellorini, Cristina (2016). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=ZtFRDQAAQBAJ&pg=PT72"><i>The World of Plants in Renaissance Tuscany: Medicine and Botany</i></a>. Abingdon-on-Thames, England: Routledge. p. 72. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781317011491" title="Special:BookSources/9781317011491"><bdi>9781317011491</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+World+of+Plants+in+Renaissance+Tuscany%3A+Medicine+and+Botany&rft.place=Abingdon-on-Thames%2C+England&rft.pages=72&rft.pub=Routledge&rft.date=2016&rft.isbn=9781317011491&rft.aulast=Bellorini&rft.aufirst=Cristina&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DZtFRDQAAQBAJ%26pg%3DPT72&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKramerBoyer1995" class="citation book cs1">Kramer, Paul J.; Boyer, John S. (1995). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=H6aHAwAAQBAJ&pg=PA2"><i>Water Relations of Plants and Soils</i></a>. London, England: Elsevier Science. p. 2. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780080924113" title="Special:BookSources/9780080924113"><bdi>9780080924113</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Water+Relations+of+Plants+and+Soils&rft.place=London%2C+England&rft.pages=2&rft.pub=Elsevier+Science&rft.date=1995&rft.isbn=9780080924113&rft.aulast=Kramer&rft.aufirst=Paul+J.&rft.au=Boyer%2C+John+S.&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DH6aHAwAAQBAJ%26pg%3DPA2&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li></ul> </span></li> <li id="cite_note-47"><span class="mw-cite-backlink"><b><a href="#cite_ref-47">^</a></b></span> <span class="reference-text">See: <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFMalpighi1675" class="citation book cs1 cs1-prop-foreign-lang-source">Malpighi, Marcello (1675). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=DBp8TQ_B0oAC&pg=PA8"><i>Anatome Plantarum ...</i></a> (in Latin). London, England, UK: Royal Society of London. p. 8.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Anatome+Plantarum+...&rft.place=London%2C+England%2C+UK&rft.pages=8&rft.pub=Royal+Society+of+London&rft.date=1675&rft.aulast=Malpighi&rft.aufirst=Marcello&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DDBp8TQ_B0oAC%26pg%3DPA8&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFJansenSchenk2015" class="citation journal cs1">Jansen, Steven; Schenk, H. Jochen (2015). <a rel="nofollow" class="external text" href="https://doi.org/10.3732%2Fajb.1500305">"On the ascent of sap in the presence of bubbles"</a>. <i>American Journal of Botany</i>. <b>102</b> (10): <span class="nowrap">1561–</span>1563. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.3732%2Fajb.1500305">10.3732/ajb.1500305</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/26400778">26400778</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=American+Journal+of+Botany&rft.atitle=On+the+ascent+of+sap+in+the+presence+of+bubbles&rft.volume=102&rft.issue=10&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1561-%3C%2Fspan%3E1563&rft.date=2015&rft_id=info%3Adoi%2F10.3732%2Fajb.1500305&rft_id=info%3Apmid%2F26400778&rft.aulast=Jansen&rft.aufirst=Steven&rft.au=Schenk%2C+H.+Jochen&rft_id=https%3A%2F%2Fdoi.org%2F10.3732%252Fajb.1500305&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li> <li>Lazenby, Elizabeth Mary (1995) "The <i>Historia Plantarum Generalis</i> of John Ray: Book I – a translation and commentary.", doctoral thesis, University of Newcastle upon Tyne, England, UK, vol. 1, p. 160. Available at: <a rel="nofollow" class="external text" href="https://theses.ncl.ac.uk/dspace/bitstream/10443/327/1/Lazenby95v.1.pdf">University of Newcastle upon Tyne, UK.</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20180814103423/https://theses.ncl.ac.uk/dspace/bitstream/10443/327/1/Lazenby95v.1.pdf">Archived</a> 2018-08-14 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></li></ul> </span></li> <li id="cite_note-49"><span class="mw-cite-backlink"><b><a href="#cite_ref-49">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFGrew1682" class="citation book cs1">Grew, Nehemiah (1682). <a rel="nofollow" class="external text" href="https://archive.org/stream/mobot31753000008869#page/123/"><i>The Anatomy of Plants ...</i></a> London, England: W. Rawlins. pp. <span class="nowrap">124–</span>125.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Anatomy+of+Plants+...&rft.place=London%2C+England&rft.pages=%3Cspan+class%3D%22nowrap%22%3E124-%3C%2Fspan%3E125&rft.pub=W.+Rawlins&rft.date=1682&rft.aulast=Grew&rft.aufirst=Nehemiah&rft_id=https%3A%2F%2Farchive.org%2Fstream%2Fmobot31753000008869%23page%2F123%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span> From pp. 124–125: "For the great part of the year, it [i.e., the sap] riseth in the <i>Barque</i> [i.e., bark], sc. in the inner <i>Margin</i> adjacent to the <i>Wood</i>, and in the <i>spring</i>, in or through the <i>Wood</i> it self, and there only."</span> </li> <li id="cite_note-50"><span class="mw-cite-backlink"><b><a href="#cite_ref-50">^</a></b></span> <span class="reference-text">See: <ul><li>(Grew, 1682), p. 126. Grew recognized the limits of capillary action (from p. 126): " ... small <i>Glass-Pipes</i> [i.e., capillary tubes] immersed in Water, will give it [i.e., the water] an ascent for some inches; yet there is a certain <i>period</i>, according to the <i>bore</i> of the <i>Pipe</i>, beyond which it will not rise." Grew proposed the following mechanism for the ascent of sap in plants (from p. 126): "But the <i>Bladders</i> [i.e., parenchymal cells] DP, which surround it [i.e., the column of tracheids], being swelled up and turgid with <i>Sap</i>, do hereby press upon it; and so not only a little contract its bore, but also transfuse or strain some <i>Portion</i> of their <i>Sap</i> thereinto: by both which means, the <i>Sap</i> will be forced to rise higher therein."</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFArber1913" class="citation book cs1">Arber, Agnes (1913). <a rel="nofollow" class="external text" href="https://www.biodiversitylibrary.org/item/16228#page/86/mode/1up">"Nehemiah Grew 1641–1712"</a>. In Oliver, Francis Wall (ed.). <i>Makers of British Botany: A Collection of Biographies by Living Botanists</i>. Cambridge, England: Cambridge University Press. p. 58.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Nehemiah+Grew+1641%E2%80%931712&rft.btitle=Makers+of+British+Botany%3A+A+Collection+of+Biographies+by+Living+Botanists&rft.place=Cambridge%2C+England&rft.pages=58&rft.pub=Cambridge+University+Press&rft.date=1913&rft.aulast=Arber&rft.aufirst=Agnes&rft_id=https%3A%2F%2Fwww.biodiversitylibrary.org%2Fitem%2F16228%23page%2F86%2Fmode%2F1up&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li></ul> </span></li> <li id="cite_note-51"><span class="mw-cite-backlink"><b><a href="#cite_ref-51">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFHales1727" class="citation book cs1">Hales, Stephen (1727). <a rel="nofollow" class="external text" href="https://archive.org/details/vegetablestatick00hale/page/100"><i>Vegetable Staticks: Or, an account of some statical experiments on the sap in vegetables: ...</i></a> London, England: W. & J. Innys and T. Woodward. p. <a rel="nofollow" class="external text" href="https://archive.org/details/vegetablestatick00hale/page/100">100</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780356030128" title="Special:BookSources/9780356030128"><bdi>9780356030128</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Vegetable+Staticks%3A+Or%2C+an+account+of+some+statical+experiments+on+the+sap+in+vegetables%3A+...&rft.place=London%2C+England&rft.pages=100&rft.pub=W.+%26+J.+Innys+and+T.+Woodward&rft.date=1727&rft.isbn=9780356030128&rft.aulast=Hales&rft.aufirst=Stephen&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fvegetablestatick00hale%2Fpage%2F100&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></span> </li> <li id="cite_note-53"><span class="mw-cite-backlink"><b><a href="#cite_ref-53">^</a></b></span> <span class="reference-text">See: <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFStrasburger1891" class="citation book cs1 cs1-prop-long-vol cs1-prop-foreign-lang-source">Strasburger, Eduard (1891). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=rjMaAAAAYAAJ&pg=PA607"><i>Histologische Beiträge</i></a> [<i>Histological Contributions</i>] (in German). Vol. 3: <i>Ueber den Bau und die Verrichtungen der Leitungsbahnen in den Pflanzen</i> [On the structure and the function of vascular bundles in plants]. Jena, Germany: Gustav Fischer. pp. 607–625: <i>Aufsteigen giftiger Flüssigkeiten bis zu bedeutender Höhe in der Pflanze</i> [Ascent of poisonous liquids to considerable heights in plants], pp. 645–671: <i>Die Leitungsfähigkeit getödteter Pflanzentheile</i> [The ability of the killed parts of plants to conduct [water]].</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Histologische+Beitr%C3%A4ge&rft.place=Jena%2C+Germany&rft.pages=607-625%3A+%27%27Aufsteigen+giftiger+Fl%C3%BCssigkeiten+bis+zu+bedeutender+H%C3%B6he+in+der+Pflanze%27%27+Ascent+of+poisonous+liquids+to+considerable+heights+in+plants%2C+pp.+645-671%3A+%27%27Die+Leitungsf%C3%A4higkeit+get%C3%B6dteter+Pflanzentheile%27%27+The+ability+of+the+killed+parts+of+plants+to+conduct+water&rft.pub=Gustav+Fischer&rft.date=1891&rft.aulast=Strasburger&rft.aufirst=Eduard&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DrjMaAAAAYAAJ%26pg%3DPA607&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li> <li>(Jansen & Schenck, 2015), p. 1561.</li></ul> </span></li> </ol></div></div> <div class="mw-heading mw-heading3"><h3 id="General_references">General references</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=15" title="Edit section: General references"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFC._WeiE._SteudleM._T._TyreeP._M._Lintilhac2001" class="citation journal cs1">C. Wei; E. Steudle; M. T. Tyree; P. M. Lintilhac (May 2001). "The essentials of direct xylem pressure measurement". <i>Plant, Cell and Environment</i>. <b>24</b> (5): <span class="nowrap">549–</span>555. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2001PCEnv..24..549W">2001PCEnv..24..549W</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1046%2Fj.1365-3040.2001.00697.x">10.1046/j.1365-3040.2001.00697.x</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:5039439">5039439</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Plant%2C+Cell+and+Environment&rft.atitle=The+essentials+of+direct+xylem+pressure+measurement&rft.volume=24&rft.issue=5&rft.pages=%3Cspan+class%3D%22nowrap%22%3E549-%3C%2Fspan%3E555&rft.date=2001-05&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A5039439%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1046%2Fj.1365-3040.2001.00697.x&rft_id=info%3Abibcode%2F2001PCEnv..24..549W&rft.au=C.+Wei&rft.au=E.+Steudle&rft.au=M.+T.+Tyree&rft.au=P.+M.+Lintilhac&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span> is the main source used for the paragraph on recent research.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFN._Michele_HolbrookMichael_J._BurnsChristopher_B._Field1995" class="citation journal cs1">N. Michele Holbrook; Michael J. Burns; Christopher B. Field (November 1995). "Negative Xylem Pressures in Plants: A Test of the Balancing Pressure Technique". <i><a href="/wiki/Science_(journal)" title="Science (journal)">Science</a></i>. <b>270</b> (5239): <span class="nowrap">1193–</span>4. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1995Sci...270.1193H">1995Sci...270.1193H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fscience.270.5239.1193">10.1126/science.270.5239.1193</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:97217181">97217181</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Science&rft.atitle=Negative+Xylem+Pressures+in+Plants%3A+A+Test+of+the+Balancing+Pressure+Technique&rft.volume=270&rft.issue=5239&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1193-%3C%2Fspan%3E4&rft.date=1995-11&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A97217181%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1126%2Fscience.270.5239.1193&rft_id=info%3Abibcode%2F1995Sci...270.1193H&rft.au=N.+Michele+Holbrook&rft.au=Michael+J.+Burns&rft.au=Christopher+B.+Field&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span> is the first published independent test showing the Scholander bomb actually does measure the tension in the xylem.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFPockman,_W.T.J.S._SperryJ.W._O'Leary1995" class="citation journal cs1">Pockman, W.T.; J.S. Sperry; J.W. O'Leary (December 1995). "Sustained and significant negative water pressure in xylem". <i><a href="/wiki/Nature_(journal)" title="Nature (journal)">Nature</a></i>. <b>378</b> (6558): <span class="nowrap">715–</span>6. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1995Natur.378..715P">1995Natur.378..715P</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2F378715a0">10.1038/378715a0</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:31357329">31357329</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Sustained+and+significant+negative+water+pressure+in+xylem&rft.volume=378&rft.issue=6558&rft.pages=%3Cspan+class%3D%22nowrap%22%3E715-%3C%2Fspan%3E6&rft.date=1995-12&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A31357329%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1038%2F378715a0&rft_id=info%3Abibcode%2F1995Natur.378..715P&rft.au=Pockman%2C+W.T.&rft.au=J.S.+Sperry&rft.au=J.W.+O%27Leary&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span> is the second published independent test showing the Scholander bomb actually does measure the tension in the xylem.</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFCampbell,_Neil_A.Jane_B._Reece2002" class="citation book cs1">Campbell, Neil A.; Jane B. Reece (2002). <a rel="nofollow" class="external text" href="https://archive.org/details/biologyc00camp"><i>Biology</i></a> (6th ed.). Benjamin Cummings. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-8053-6624-2" title="Special:BookSources/978-0-8053-6624-2"><bdi>978-0-8053-6624-2</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Biology&rft.edition=6th&rft.pub=Benjamin+Cummings&rft.date=2002&rft.isbn=978-0-8053-6624-2&rft.au=Campbell%2C+Neil+A.&rft.au=Jane+B.+Reece&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fbiologyc00camp&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKenrick,_PaulCrane,_Peter_R.1997" class="citation book cs1">Kenrick, Paul; Crane, Peter R. (1997). <i>The Origin and Early Diversification of Land Plants: A Cladistic Study</i>. Washington, D. C.: Smithsonian Institution Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-56098-730-7" title="Special:BookSources/978-1-56098-730-7"><bdi>978-1-56098-730-7</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Origin+and+Early+Diversification+of+Land+Plants%3A+A+Cladistic+Study&rft.place=Washington%2C+D.+C.&rft.pub=Smithsonian+Institution+Press&rft.date=1997&rft.isbn=978-1-56098-730-7&rft.au=Kenrick%2C+Paul&rft.au=Crane%2C+Peter+R.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFMuhammad,_A._F.R._Sattler1982" class="citation journal cs1">Muhammad, A. F.; R. Sattler (1982). "Vessel Structure of <i>Gnetum</i> and the Origin of Angiosperms". <i>American Journal of Botany</i>. <b>69</b> (6): <span class="nowrap">1004–</span>21. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.2307%2F2442898">10.2307/2442898</a>. <a href="/wiki/JSTOR_(identifier)" class="mw-redirect" title="JSTOR (identifier)">JSTOR</a> <a rel="nofollow" class="external text" href="https://www.jstor.org/stable/2442898">2442898</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=American+Journal+of+Botany&rft.atitle=Vessel+Structure+of+Gnetum+and+the+Origin+of+Angiosperms&rft.volume=69&rft.issue=6&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1004-%3C%2Fspan%3E21&rft.date=1982&rft_id=info%3Adoi%2F10.2307%2F2442898&rft_id=https%3A%2F%2Fwww.jstor.org%2Fstable%2F2442898%23id-name%3DJSTOR&rft.au=Muhammad%2C+A.+F.&rft.au=R.+Sattler&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFMelvin_T._TyreeMartin_H._Zimmermann2003" class="citation book cs1">Melvin T. Tyree; Martin H. Zimmermann (2003). <i>Xylem Structure and the Ascent of Sap</i> (2nd ed.). Springer. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-540-43354-5" title="Special:BookSources/978-3-540-43354-5"><bdi>978-3-540-43354-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Xylem+Structure+and+the+Ascent+of+Sap&rft.edition=2nd&rft.pub=Springer&rft.date=2003&rft.isbn=978-3-540-43354-5&rft.au=Melvin+T.+Tyree&rft.au=Martin+H.+Zimmermann&rfr_id=info%3Asid%2Fen.wikipedia.org%3AXylem" class="Z3988"></span> recent update of the classic book on xylem transport by the late Martin Zimmermann</li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Xylem&action=edit&section=16" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Commons-logo.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/40px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span> Media related to <a href="https://commons.wikimedia.org/wiki/Category:Xylem" class="extiw" title="commons:Category:Xylem">Xylem</a> at Wikimedia Commons</li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Biological_tissues259" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374" /><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Biological_tissues" title="Template:Biological tissues"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Biological_tissues" title="Template talk:Biological tissues"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Biological_tissues" title="Special:EditPage/Template:Biological tissues"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Biological_tissues259" style="font-size:114%;margin:0 4em"><a href="/wiki/Tissue_(biology)" title="Tissue (biology)">Biological tissues</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Tissue_(biology)#Animal_tissues" title="Tissue (biology)">Animals</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Connective_tissue" title="Connective tissue">Connective</a></li> <li><a href="/wiki/Epithelium" title="Epithelium">Epithelial</a></li> <li><a href="/wiki/Muscle_tissue" class="mw-redirect" title="Muscle tissue">Muscular</a></li> <li><a href="/wiki/Nervous_tissue" title="Nervous tissue">Nervous</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Tissue_(biology)#Plant_tissues" title="Tissue (biology)">Plants</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i>Dermal tissue</i>: <b><a href="/wiki/Epidermis_(botany)" title="Epidermis (botany)">Epidermis</a></b> <ul><li><a href="/wiki/Bulliform_cell" title="Bulliform cell">Bulliform cell</a></li> <li><a href="/wiki/Plant_cuticle" title="Plant cuticle">Cuticle</a></li> <li><a href="/wiki/Guard_cell" title="Guard cell">Guard cell</a></li> <li><a href="/wiki/Epidermis_(botany)" title="Epidermis (botany)">Pavement cell</a></li> <li><a href="/wiki/Epidermis_(botany)" title="Epidermis (botany)">Subsidiary cell</a></li></ul></li> <li><b><a href="/wiki/Periderm" class="mw-redirect" title="Periderm">Periderm</a></b> <ul><li><a href="/wiki/Phellem" class="mw-redirect" title="Phellem">Phellem</a></li> <li><a href="/wiki/Phelloderm" class="mw-redirect" title="Phelloderm">Phelloderm</a></li></ul></li></ul> <ul><li><i><a href="/wiki/Vascular_tissue" title="Vascular tissue">Vascular tissue</a></i>: <b><a href="/wiki/Phloem" title="Phloem">Phloem</a></b> <ul><li><a href="/wiki/Companion_cell" class="mw-redirect" title="Companion cell">Companion cell</a></li> <li><a href="/wiki/Bast_fibre" title="Bast fibre">Phloem fiber</a></li> <li><a href="/wiki/Phloem#Parenchyma_cells" title="Phloem">Phloem parenchyma</a></li> <li><a href="/wiki/Sieve_tube" class="mw-redirect" title="Sieve tube">Sieve tube</a></li></ul></li> <li><b><a class="mw-selflink selflink">Xylem</a></b> <ul><li><a href="/wiki/Tracheid" title="Tracheid">Tracheid</a></li> <li><a href="/wiki/Vessel_element" title="Vessel element">Vessel element</a></li> <li><a class="mw-selflink selflink">Xylem fiber</a></li> <li><a class="mw-selflink selflink">Xylem parenchyma</a></li></ul></li></ul> <ul><li><i><a href="/wiki/Ground_tissue" title="Ground tissue">Ground tissue</a></i>: <b><a href="/wiki/Ground_tissue#Parenchyma" title="Ground tissue">Parenchyma</a></b> <ul><li><a href="/wiki/Aerenchyma" title="Aerenchyma">Aerenchyma</a></li> <li><a href="/wiki/Chlorenchyma" class="mw-redirect" title="Chlorenchyma">Chlorenchyma</a></li> <li><a href="/wiki/Mesophyll" class="mw-redirect" title="Mesophyll">Mesophyll</a></li> <li><a href="/wiki/Pith" title="Pith">Pith</a></li></ul></li> <li><b><a href="/wiki/Collenchyma" class="mw-redirect" title="Collenchyma">Collenchyma</a></b></li> <li><b><a href="/wiki/Sclerenchyma" class="mw-redirect" title="Sclerenchyma">Sclerenchyma</a></b> <ul><li><a href="/wiki/Ground_tissue#Fibers" title="Ground tissue">Fiber</a></li> <li><a href="/wiki/Sclereid" title="Sclereid">Sclereid</a></li></ul></li></ul> <ul><li><i><a href="/wiki/Meristem" title="Meristem">Meristematic tissue</a></i>: <b><a href="/wiki/Meristem#Primary_meristems" title="Meristem">Primary</a></b> <ul><li><a href="/wiki/Ground_meristem" class="mw-redirect" title="Ground meristem">Ground meristem</a></li> <li><a href="/wiki/Procambium" class="mw-redirect" title="Procambium">Procambium</a></li> <li><a href="/wiki/Protoderm" class="mw-redirect" title="Protoderm">Protoderm</a></li></ul></li> <li><b><a href="/wiki/Meristem#Secondary_meristems" title="Meristem">Secondary</a></b> <ul><li><a href="/wiki/Cork_cambium" title="Cork cambium">Cork cambium</a></li> <li><a href="/wiki/Vascular_cambium" title="Vascular cambium">Vascular cambium</a></li></ul></li></ul> <ul><li><i>Mixed</i>: <b><a href="/wiki/Cortex_(botany)" title="Cortex (botany)">Cortex</a></b> <ul><li><a href="/wiki/Endodermis" title="Endodermis">Endodermis</a></li> <li><a href="/wiki/Exodermis" title="Exodermis">Exodermis</a></li></ul></li> <li><b><a href="/wiki/Stele_(biology)" title="Stele (biology)">Stele</a></b></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Tissues_(biology)" title="Category:Tissues (biology)">Category</a></li> <li><a href="/wiki/Histology" title="Histology">Histology</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235" /><style data-mw-deduplicate="TemplateStyles:r1038841319">.mw-parser-output .tooltip-dotted{border-bottom:1px dotted;cursor:help}</style></div><div role="navigation" class="navbox authority-control" aria-label="Navbox639" style="padding:3px"><table class="nowraplinks hlist navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Help:Authority_control" title="Help:Authority control">Authority control databases</a>: National <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q122811#identifiers" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="Xylem"><a rel="nofollow" class="external text" href="https://d-nb.info/gnd/4190391-2">Germany</a></span></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://dbn.bn.org.pl/descriptor-details/9810541504405606">Poland</a></span></li></ul></div></td></tr></tbody></table></div>    </div><noscript><img src="https://auth.wikimedia.org/loginwiki/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Xylem&oldid=1282031809">https://en.wikipedia.org/w/index.php?title=Xylem&oldid=1282031809</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Plant_anatomy" title="Category:Plant anatomy">Plant anatomy</a></li><li><a href="/wiki/Category:Plant_cells" title="Category:Plant cells">Plant cells</a></li><li><a href="/wiki/Category:Plant_physiology" title="Category:Plant physiology">Plant physiology</a></li><li><a href="/wiki/Category:Tissues_(biology)" title="Category:Tissues (biology)">Tissues (biology)</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:CS1_German-language_sources_(de)" title="Category:CS1 German-language sources (de)">CS1 German-language sources (de)</a></li><li><a href="/wiki/Category:Webarchive_template_wayback_links" title="Category:Webarchive template wayback links">Webarchive template wayback links</a></li><li><a href="/wiki/Category:CS1_maint:_multiple_names:_authors_list" title="Category:CS1 maint: multiple names: authors list">CS1 maint: multiple names: authors list</a></li><li><a href="/wiki/Category:CS1_Hungarian-language_sources_(hu)" title="Category:CS1 Hungarian-language sources (hu)">CS1 Hungarian-language sources (hu)</a></li><li><a href="/wiki/Category:All_articles_with_dead_external_links" title="Category:All articles with dead external links">All articles with dead external links</a></li><li><a href="/wiki/Category:Articles_with_dead_external_links_from_October_2023" title="Category:Articles with dead external links from October 2023">Articles with dead external links from October 2023</a></li><li><a href="/wiki/Category:Articles_with_permanently_dead_external_links" title="Category:Articles with permanently dead external links">Articles with permanently dead external links</a></li><li><a href="/wiki/Category:CS1_Latin-language_sources_(la)" title="Category:CS1 Latin-language sources (la)">CS1 Latin-language sources (la)</a></li><li><a href="/wiki/Category:CS1:_long_volume_value" title="Category:CS1: long volume value">CS1: long volume value</a></li><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:All_articles_with_unsourced_statements" title="Category:All articles with unsourced statements">All articles with unsourced statements</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_January_2025" title="Category:Articles with unsourced statements from January 2025">Articles with unsourced statements from January 2025</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_March_2019" title="Category:Articles with unsourced statements from March 2019">Articles with unsourced statements from March 2019</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_October_2023" title="Category:Articles with unsourced statements from October 2023">Articles with unsourced statements from October 2023</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_November_2022" title="Category:Articles with unsourced statements from November 2022">Articles with unsourced statements from November 2022</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_February_2015" title="Category:Articles with unsourced statements from February 2015">Articles with unsourced statements from February 2015</a></li><li><a href="/wiki/Category:Commons_category_link_from_Wikidata" title="Category:Commons category link from Wikidata">Commons category link from Wikidata</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 23 March 2025, at 22:00<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Xylem&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://www.wikimedia.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><picture><source media="(min-width: 500px)" srcset="/static/images/footer/wikimedia-button.svg" width="84" height="29"><img src="/static/images/footer/wikimedia.svg" width="25" height="25" alt="Wikimedia Foundation" lang="en" loading="lazy"></picture></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><picture><source media="(min-width: 500px)" srcset="/w/resources/assets/poweredby_mediawiki.svg" width="88" height="31"><img src="/w/resources/assets/mediawiki_compact.svg" alt="Powered by MediaWiki" lang="en" width="25" height="25" loading="lazy"></picture></a></li> </ul> </footer> </div> </div> </div> <div class="vector-header-container vector-sticky-header-container"> <div id="vector-sticky-header" class="vector-sticky-header"> <div class="vector-sticky-header-start"> <div class="vector-sticky-header-icon-start vector-button-flush-left vector-button-flush-right" aria-hidden="true"> <button class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-sticky-header-search-toggle" tabindex="-1" data-event-name="ui.vector-sticky-search-form.icon"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </button> </div> <div role="search" class="vector-search-box-vue vector-search-box-show-thumbnail vector-search-box"> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail"> <form action="/w/index.php" id="vector-sticky-search-form" class="cdx-search-input cdx-search-input--has-end-button"> <div class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia"> <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <div class="vector-sticky-header-context-bar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-sticky-header-toc" class="vector-dropdown mw-portlet mw-portlet-sticky-header-toc vector-sticky-header-toc vector-button-flush-left" > <input type="checkbox" id="vector-sticky-header-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-sticky-header-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-sticky-header-toc-label" for="vector-sticky-header-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-sticky-header-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div class="vector-sticky-header-context-bar-primary" aria-hidden="true" ><span class="mw-page-title-main">Xylem</span></div> </div> </div> <div class="vector-sticky-header-end" aria-hidden="true"> <div class="vector-sticky-header-icons"> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-talk-sticky-header" tabindex="-1" data-event-name="talk-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbles mw-ui-icon-wikimedia-speechBubbles"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-subject-sticky-header" tabindex="-1" data-event-name="subject-sticky-header"><span class="vector-icon mw-ui-icon-article mw-ui-icon-wikimedia-article"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-history-sticky-header" tabindex="-1" data-event-name="history-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-history mw-ui-icon-wikimedia-wikimedia-history"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only mw-watchlink" id="ca-watchstar-sticky-header" tabindex="-1" data-event-name="watch-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-star mw-ui-icon-wikimedia-wikimedia-star"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-edit-sticky-header" tabindex="-1" data-event-name="wikitext-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-wikiText mw-ui-icon-wikimedia-wikimedia-wikiText"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-ve-edit-sticky-header" tabindex="-1" data-event-name="ve-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-edit mw-ui-icon-wikimedia-wikimedia-edit"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-viewsource-sticky-header" tabindex="-1" data-event-name="ve-edit-protected-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-editLock mw-ui-icon-wikimedia-wikimedia-editLock"></span> <span></span> </a> </div> <div class="vector-sticky-header-buttons"> <button class="cdx-button cdx-button--weight-quiet mw-interlanguage-selector" id="p-lang-btn-sticky-header" tabindex="-1" data-event-name="ui.dropdown-p-lang-btn-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-language mw-ui-icon-wikimedia-wikimedia-language"></span> <span>68 languages</span> </button> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive" id="ca-addsection-sticky-header" tabindex="-1" data-event-name="addsection-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbleAdd-progressive mw-ui-icon-wikimedia-speechBubbleAdd-progressive"></span> <span>Add topic</span> </a> </div> <div class="vector-sticky-header-icon-end"> <div class="vector-user-links"> </div> </div> </div> </div> </div> <div class="mw-portlet mw-portlet-dock-bottom emptyPortlet" id="p-dock-bottom"> <ul> </ul> </div> <script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-6f5b484c85-gr26r","wgBackendResponseTime":180,"wgPageParseReport":{"limitreport":{"cputime":"0.829","walltime":"0.964","ppvisitednodes":{"value":6450,"limit":1000000},"postexpandincludesize":{"value":168208,"limit":2097152},"templateargumentsize":{"value":8910,"limit":2097152},"expansiondepth":{"value":17,"limit":100},"expensivefunctioncount":{"value":8,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":237502,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 849.841 1 -total"," 43.02% 365.565 2 Template:Reflist"," 18.54% 157.547 28 Template:Cite_journal"," 11.62% 98.751 25 Template:Cite_book"," 11.08% 94.185 1 Template:Wikt-lang"," 9.44% 80.225 13 Template:Fix"," 9.06% 77.034 5 Template:Cite_web"," 8.81% 74.833 1 Template:Short_description"," 8.19% 69.568 1 Template:Biological_tissue"," 8.03% 68.248 8 Template:Cn"]},"scribunto":{"limitreport-timeusage":{"value":"0.548","limit":"10.000"},"limitreport-memusage":{"value":25337526,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-684955989f-4lgrb","timestamp":"20250331175001","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Xylem","url":"https:\/\/en.wikipedia.org\/wiki\/Xylem","sameAs":"http:\/\/www.wikidata.org\/entity\/Q122811","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q122811","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2002-03-30T02:46:05Z","dateModified":"2025-03-23T22:00:09Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/6\/6d\/Xylem_and_phloem_diagram.svg","headline":"one of the two types of transport tissue in vascular plants"}</script> </body> </html>