{{Short description|Species of grass-like plant}} {{Italic title}} {{speciesbox | name = Needle spikerush | image = Eleocharis acicularis.jpeg | genus = Eleocharis | species = acicularis | authority = (L.) Roem. & Schult. | synonyms = {{Plainlist | style = margin-left: 1em; text-indent: -1em; | * ''Baeothryon trichoides'' <small>(Kunth) A.Dietr.</small> * ''Chaetocyperus acicularis'' <small>(L.) Nees</small> * ''Chaetocyperus trichodes'' <small>(Muhl.) Steud.</small> * ''Clavula acicularis'' <small>(L.) Dumort.</small> * ''Cyperus acicularis'' <small>(L.) With.</small> * ''Eleocharis atricha'' <small>Benth.</small> nom. illeg. * ''Eleocharis chaetaria'' <small>Hance</small> nom. illeg. * ''Eleocharis comosa'' <small>K.Richt.</small> * ''Eleocharis costata'' <small>J.Presl & C.Presl</small> * ''Eleocharis nervata'' <small>Svenson</small> * ''Eleocharis triangularis'' <small>Reinsch</small> * ''Eleocharis trichoides'' <small>(Kunth) Kuntze</small> * ''Eleogiton exigua'' <small>A.Dietr.</small> * ''Isolepis acicularis'' <small>(L.) Schltdl.</small> * ''Isolepis exigua'' <small>Hook. & Arn.</small> * ''Isolepis longifolia'' <small>Steud.</small> * ''Isolepis uliginosa'' <small>Steud.</small> * ''Limnochloa acicularis'' <small>(L.) Rchb.</small> * ''Limnochloa costulata'' <small>Nees ex Kunth</small> nom. inval. * ''Mariscus acicularis'' <small>(L.) Moench</small> * ''Scirpidium aciculare'' <small>(L.) Nees</small> * ''Scirpus acicularis'' <small>L.</small> * ''Scirpus chaeta'' <small>Schult.</small> * ''Scirpus polymorphus'' <small>Salzm. ex Steud.</small> * ''Scirpus pusillus'' <small>Kunth</small> * ''Scirpus trichodes'' <small>Muhl.</small> * ''Scirpus trichoides'' <small>Kunth</small> * ''Scirpus uliginosus'' <small>K.Koch</small> nom. illeg. * ''Trichophyllum aciculare'' <small>(L.) House</small> }} | synonyms_ref = <ref>{{cite web |url=http://www.theplantlist.org/tpl1.1/record/kew-242255 |title=The Plant List: A Working List of All Plant Species |accessdate=4 January 2015}}</ref> }}
'''''Eleocharis acicularis''''' is a species of spikesedge known by the common names '''needle spikerush'''<ref>{{PLANTS|id=ELAC|taxon=Eleocharis acicularis|accessdate=18 January 2016}}</ref> and '''least spikerush'''. It is widespread across Europe, central and southeastern Asia, North America and northeastern South America as far south as Ecuador.<ref name="wcsp">[http://apps.kew.org/wcsp/namedetail.do?name_id=242255 Kew World Checklist of Selected Plant Families]</ref> It is also found in Australia, where it is probably an introduced species.<ref name="lippi">[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242357729 Flora of North America, Vol. 23 Page 108, ''Eleocharis acicularis'' (Linnaeus) Roemer & Schultes in J. J. Roemer et al., Syst. Veg. 2: 154. 1817.]</ref>
''Eleocharis acicularis'' is an annual or perennial spikesedge with long, grasslike stems to about 15 centimeters (6 inches) in height, shorter in bog conditions, from a creeping rhizome. In shallow water it will form short spikes of tiny flowers amongst flat overlapping bracts. The tiny flowers are less than five millimeters in diameter and are borne at the tip of each stem in single, sharply pointed, lanceoloid spikelets up to about six millimeters long. This is a plant of marshes, vernal pools, and bogs.<ref name="lippi" />
''Eleocharis acicularis'' is sold commercially as an aquascape plant suitable for inclusion in artificial aquatic environments. It thrives with plenty of light and a high concentration of carbon dioxide.<ref>Roe, Colin D. (1967), ''A Manual of Aquarium Plants'', Shirley Aquatics, Solihull</ref><ref>{{Cite web |url=http://www.aquascapingworld.com/plantpedia/full_view_plant.php?item_id=46&plant=Eleocharis%20acicularis |title=Aquascaping World Plantpedia, ''Eleocharis acicularis'' |access-date=2014-07-25 |archive-date=2014-07-28 |archive-url=https://web.archive.org/web/20140728202331/http://www.aquascapingworld.com/plantpedia/full_view_plant.php?item_id=46&plant=Eleocharis%20acicularis |url-status=dead }}</ref>
The specific epithet, {{lang|la|acicularis}}, is derived from Latin and means "needle-shaped".<ref name="Eggli Newton 2004">{{cite book |last=Eggli |first=Urs |last2=Newton |first2=Leonard E. |title=Etymological Dictionary of Succulent Plant Names |publisher=Springer |location=Berlin, Heidelberg |year=2004 |isbn=978-3-540-00489-9 |url=https://books.google.com/books?id=u2n5vusQ1DEC&pg=PA1 |access-date=14 November 2018 |page=1}}</ref>
== Varieties == Two varieties are recognized:<ref name="wcsp" />
* ''Eleocharis acicularis'' var. ''acicularis'' – most of species range * ''Eleocharis acicularis'' var. ''porcata'' <small>S.G.Sm.</small> – western North America from Alberta south to New Mexico and Louisiana
== References == {{Reflist}}
== External links == {{commonscat-inline}} * [http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?7928,8103,8104 Jepson Manual Treatment] * [http://www.wetwebmedia.com/plantedtkssubwebindex/eleocharis.htm WetWebMedia: Hair Grass] {{Webarchive|url=https://web.archive.org/web/20140222163128/http://www.wetwebmedia.com/plantedtkssubwebindex/eleocharis.htm |date=2014-02-22 }} * [https://www.npwrc.usgs.gov/resource/plants/vascplnt/species/eaci.htm USGS Species Profile] * [https://web.archive.org/web/20140222205651/http://www.ecy.wa.gov/Programs/wq/plants/plantid2/descriptions/ele.html Washington State Water Quality Program]
{{Taxonbar|from=Q159148}}
Acicularis Category:Flora of Northern America Category:Flora of Southern America Category:Flora of Europe Category:Flora of Asia Category:Plants described in 1753 Category:Botanical taxa named by Carl Linnaeus Category:Freshwater plants
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