{{Short description|Species of plant}} {{Speciesbox | image = Alisma lanceolatum 229627808.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 20 November 2021">{{cite iucn |author=Akhani, H. |author2=Zehzad, B. |date=2014 |title=''Alisma lanceolatum'' |volume=2014 |article-number=e.T163974A42307131 |doi=10.2305/IUCN.UK.2014-1.RLTS.T163974A42307131.en |access-date=20 November 2021}}</ref> | status2 = G4 | status2_system = TNC | status2_ref = <ref>{{Cite web|title=NatureServe Explorer|url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.155791/Alisma_lanceolatum|access-date=2021-04-22}}</ref> | genus = Alisma | species = lanceolatum | authority = With. }}
'''''Alisma lanceolatum''''' is a species of aquatic plant in the water plantain family known by the common names '''lanceleaf water plantain''' and '''narrow-leaved water plantain'''.<ref name=BSBI07>{{BSBI 2007 |access-date=2014-10-17 }}</ref> It is widespread across Europe, North Africa and temperate Asia.<ref name=":1" /> It is naturalized in Australia, New Zealand, Oregon, California and British Columbia. It is considered a noxious weed in some places.<ref>{{Cite web|url=http://apps.kew.org/wcsp/namedetail.do?name_id=294813|title=World Checklist of Selected Plant Families: Royal Botanic Gardens, Kew|website=apps.kew.org|language=en-GB|access-date=2017-01-26}}</ref><ref>[http://bonap.net/MapGallery/County/Alisma%20lanceolatum.png Biota of North America Program]</ref><ref>{{Cite web|url=http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=222000006|title=Alisma lanceolatum in Flora of China @ efloras.org|website=www.efloras.org|access-date=2017-01-26}}</ref><ref>{{Cite web|url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=222000006|title=Alisma lanceolatum in Flora of North America @ efloras.org|website=www.efloras.org|access-date=2017-01-26}}</ref>
This species is a weed of rice fields in many areas, including New South Wales and California.
In England and Wales it is occasionally locally found, in Ireland it is rare, and Scotland it is very rare.
It is found in mud and in fresh waters.
==Description== thumb|left|150px|Part of an inflorescence and single blossom This is a perennial herb growing from a caudex in the water or mud that typically reaches a height of about 0.7 meters and a spread of 0.25 meters.<ref name=":0" /> It produces lance-shaped leaves 12 to 20 centimeters long and 4 wide on long petioles; leaves which remain submerged in water are smaller and less prominently veined. The inflorescence is mostly erect and up to half a meter tall.
It produces a wide array of small pinkish-purple three-petalled flowers that open in the morning, from June until August.<ref name=":2">{{Cite web|title=Irish Wildflowers - Narrow-leaved Water-plantain, Alisma lanceolatum|url=http://www.irishwildflowers.ie/pages/416a.html|access-date=2021-04-22|website=www.irishwildflowers.ie}}</ref> The fruit is a tiny achene up to 2 or 3 millimeters long clustered into an aggregate fruit of about 20 units. The seeds are reddish-brown and about 1.5 millimeters long.<ref name=":1">{{Cite web|title=Alisma lanceolatum: Narrow-leaved Water-plantain {{!}} NBN Atlas|url=https://species.nbnatlas.org/species/NBNSYS0000002102|access-date=2021-04-22|website=species.nbnatlas.org}}</ref>
== Cultivation == Grows best in water 15-30 centimeters deep in full sun. Suitable for USDA hardiness zones 5–8.<ref name=":0">{{Cite web|last=Shoot|title=Alisma lanceolatum Narrow-leaved water plantain Care Plant Varieties & Pruning Advice|url=http://www.shootgardening.co.uk/plant/alisma-lanceolatum|access-date=2021-04-22|website=www.shootgardening.co.uk|language=en}}</ref>
==Similar Species== The water plantain ''Alisma plantago-aquatica'' has acute leaf tips not tapering to a stalk.<ref name="The Wild Flower Key">{{cite book |last=Rose |first=Francis|author-link=Francis Rose |title=The Wild Flower Key |year=2006 |publisher=Frederick Warne & Co|isbn=978-0-7232-5175-0 |pages=483–484}}</ref> The flowers of ''A. plantago-aquatica'' also typically open in the afternoon, and the leaves are wider.<ref name=":2" />
==References== {{Reflist}}
==External links== {{Commons}} *[http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?7883,7884,7886 Jepson Manual Treatment] *[https://web.archive.org/web/20080726015443/http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=plant.tpl&state=&s=&ibra=all&card=W06 Weeds Australia ''Alisma lanceolatum''] *[http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=169 Calflora taxon report ''Alisma lanceolatum''] *[http://luirig.altervista.org/flora/taxa/index1.php?scientific-name=alisma+lanceolatum Altervista Flora Italiana, Mestolaccia lanceolata, ''Alisma lanceolatum''] *[http://www.florealpes.com/fiche_alismalanceolatum.php Flore Alpes, Alisma lancéolé, ''Alisma lanceolatum''] *[http://www.jardindupicvert.com/4daction/w_partner/plantain_eau_feuilles_lanceolees_alisma_lanceolatum.5877 Le Jardin du Pic Vert, Plantain d'eau à feuilles lancéolées, ''Alisma lanceolatum''] *[http://www.flora-on.pt/index.php?q=Alisma+lanceolatum Flora On Portugal, ''Alisma lanceolatum''] *[http://www.nzpcn.org.nz/flora_details.aspx?ID=2460 New Zealand Plant Conservation Network, ''Alisma lanceolatum''] *[http://wilde-planten.nl/slanke%20waterweegbree.htm Wilde Plante in Nederland en Belgie, Slanke waterweegbree (Middelste waterweegbree), Ier kikkertsblêd, Narrow-leaved Water-plantain, Plantain lancéolé (Plantain d'eau lancéolé), Lanzettblättriger Froschlöffel, ''Alisma lanceolatum''] {{Webarchive|url=https://web.archive.org/web/20140512225314/http://wilde-planten.nl/slanke%20waterweegbree.htm |date=2014-05-12 }}
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lanceolatum Category:Freshwater plants Category:Plants described in 1796 Category:Flora of the Canary Islands Category:Flora of Switzerland Category:Flora of Portugal Category:Flora of Russia Category:Flora of Central Asia Category:Flora of Siberia Category:Flora of China Category:Flora of Asia Category:Flora of Europe Category:Flora of Australia Category:Flora of New Zealand Category:Flora of California Category:Flora of British Columbia