View source for Eleocharis acicularis

{{Treatment/ID
|accepted_name=Eleocharis acicularis
|accepted_authority=(Linnaeus) Roemer & Schultes
|publications={{Treatment/Publication
|title=in J. J. Roemer et al., Syst. Veg.
|place=2: 154. 1817
|year=1817
}}
|common_names=Needle spike-rush (spikesedge);éléocharide aciculaire
|special_status={{Treatment/ID/Special_status
|code=W2
|label=
}}{{Treatment/ID/Special_status
|code=W1
|label=
}}{{Treatment/ID/Special_status
|code=F
|label=Illustrated
}}
|basionyms={{Treatment/ID/Basionym
|name=Scirpus acicularis
|authority=Linnaeus
|rank=species
|publication_title=Sp. Pl.
|publication_place=1: 48. 1753
}}
|synonyms={{Treatment/ID/Synonym
|name=Eleocharis acicularis var. gracilescens
|authority=Svenson
|rank=variety
}} {{Treatment/ID/Synonym
|name=Eleocharis acicularis var. occidentalis
|authority=Svenson
|rank=variety
}} {{Treatment/ID/Synonym
|name=Eleocharis acicularis var. porcata
|authority=S. G. Smith
|rank=variety
}} {{Treatment/ID/Synonym
|name=Eleocharis acicularis var. submersa
|authority=(Nilsson) Svenson
|rank=variety
}}
|hierarchy=Cyperaceae;Eleocharis;Eleocharis subg. Scirpidium;Eleocharis acicularis
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Cyperaceae]]</div><div class="higher-taxon"><small>genus</small>[[Eleocharis]]</div><div class="higher-taxon"><small>subgenus</small>[[Eleocharis subg. Scirpidium]]</div><div class="higher-taxon"><small>species</small>[[Eleocharis acicularis]]</div></div>
|volume=Volume 23
|mention_page=page 62, 107, 109, 110, 111
|treatment_page=page 108
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>perennial; rhizomes 0.25–0.5 mm thick, internodes 5–15 mm, scales fugaceous, rarely evident, translucent, 2 mm. <b>Culms</b> sometimes arching, smooth or 3–12-ridged, terete to sometimes distinctly compressed, 1–60 cm × 0.2–0.5(–0.7) mm, flaccid to rigid. <b>Leaves</b>: distal leaf sheaths persistent or fugaceous, proximally stramineous to red, distally colorless to stramineous or whitish, closely sheathing to prominently inflated, often splitting adaxially, apex rounded (to acute). <b>Spikelets</b> ovoid to lanceoloid or subcylindric, 2–8 × 1–2 mm, apex acute; floral scales 4–25, 4–6 per mm of rachilla, bright reddish or purplish brown to stramineous, midrib region often green, ovate, 1.5–2.5(–3.5) × 1–1.5 mm, midrib prominent to obscure, apex blunt to acute. <b>Flowers</b>: perianth bristles mostly absent, uncommonly 2–4, whitish to pale brownish, slender, obscurely retrorsely and spreading-spinulose, shorter than to equaling achene; stamens 3; anthers yellow to brown, 0.7–1.5 mm. <b>Achenes</b> with angles plus longitudinal ridges ca. 8–12, obscure to prominent, narrowly to broadly obovoid to obpyriform, 2 times to much less than 2 times longer than wide, 0.7–1.1 × 0.35–0.6 mm, trabeculae 30–60, clearly evident to crowded and obscure, spaces between trabeculae sometimes translucent. <b>Tubercles</b> gray to greenish or brownish, pyramidal to much depressed, (0.05–)0.1–0.2 × 0.15–0.25 mm. <b>2n</b> = 20.</span><!--

-->{{Treatment/Body
|phenology=Fruiting spring–fall.
|habitat=Bare, wet soil or in fresh (rarely brackish) lakes, ponds, vernal pools, meadows, springs, disturbed places
|elevation=0–3300 m
|distribution=Greenland;Alta.;B.C.;Man.;N.B.;Nfld. and Labr.;N.W.T.;N.S.;Nunavut;Ont.;P.E.I.;Que.;Sask.;Yukon;Alaska;Ariz.;Ark.;Calif.;Colo.;Conn.;Del.;D.C.;Ga.;Idaho;Ill.;Ind.;Iowa;Kans.;Ky.;La.;Maine;Md.;Mass.;Mich.;Minn.;Miss.;Mo.;Mont.;Nebr.;Nev.;N.H.;N.J.;N.Mex.;N.Y.;N.C.;N.Dak.;Ohio;Okla.;Oreg.;Pa.;R.I.;S.C.;S.Dak.;Tenn.;Tex.;Utah;Vt.;Va.;Wash.;W.Va.;Wis.;Wyo.;Mexico;Central America;South America (Ecuador);Eurasia;Australia (probably introduced).
|discussion=<p><i>Eleocharis acicularis</i> is abundant and ecologically important throughout much of its range. It occurs in a wide variety of habitats, including acid waters. I have not seen voucher specimens for reports from Alabama and Florida. I have not seen vouchers for the reported chromosome numbers of 2n = 30–38 or 50–58.</p><!--
--><p><i>Eleocharis acicularis</i> often forms large rooted mats or floating masses, which when submerged, are often non-flowering. Submerged, usually nonflowering plants are abundant throughout much of the range of the species (H. K. Svenson 1929; P. E. Rothrock and R. H. Wagner 1975). They have been called <i>E. acicularis</i> forma fluitans (Doellinger) Svenson; <i>E. acicularis</i> forma inundata Svenson; <i>E. acicularis</i> forma longicaulis (Desmazières) Hegi; <i>E. acicularis</i> forma submersa (Nilsson) Norman; and <i>E. acicularis</i> var. submersa (Nilsson) Svenson. The culms of the submerged plants are terete, smooth, soft to flaccid, translucent, and the partitions of the air cavities within are clearly visible. Submerged plants may closely resemble aquatic forms of some other species, especially <i>Eleocharis parvula</i>, <i>E. robbinsii</i>, and <i>Schoenoplectus subterminalis</i> (Torrey) Sojak (N. C. Fassett 1957; E. G. Voss 1967, 1972–1996, vol. 3).</p><!--
--><p>Although <i>E. acicularis</i> is very variable, recognition of varieties is premature pending a worldwide taxonomic revision of subg. Scirpidium. Much of the variation is apparently due to phenotypic plasticity in response to environmental factors, especially water depth (P. E. Rothrock and R. H. Wagner 1975). The named varieties intergrade extensively, and achenes, which are important in defining the varieties, are often absent. H. K. Svenson (1929) recognized four varieties and two forms for North America, but later (1957) did not recognize infraspecific taxa.</p><!--
--><p>Most plants from the Arctic to cool-temperate North America, including higher elevations in the Southwest, are very similar to plants from northern Europe and presumably belong to typical <i>E. acicularis</i>, which was described from Europe. Those plants have culms cylindric or three- to four-angled; leaf sheaths mostly obscure and closely sheathing; and achenes about two times longer than wide.</p><!--
--><p><i>Eleocharis acicularis</i> var. gracilescens Svenson, type from St. Louis, Missouri, applies to plants with flowering culms unusually long (to 60 cm), smooth or sometimes with five to twelve fine ridges, their bases not cormlike; spikelets often linear-lanceoloid, often unusually long (to 8 mm); floral scales often unusually long (to 3.5 mm), often stramineous; and achenes much less than two times longer than wide. Plants of <i>E. acicularis</i> var. gracilescens are probably usually emergent in shallow water; they are known from scattered collections from Alabama, Florida, Kansas, Missouri, North Dakota, Oklahoma, South Carolina, Tennessee, and Texas. Robust plants of <i>E. acicularis</i> var. gracilescens are sometimes misidentified as <i>E. wolfii</i>. H. K. Svenson (1957) stated that var. gracilescens may be distinct from <i>E. acicularis</i>. Some specimens from California and Oregon that resemble <i>E. acicularis</i> var. gracilescens may be ecologic forms of <i>E. acicularis</i> <i></i>var.<i> occidentalis</i>.</p><!--
--><p><i>Eleocharis acicularis</i> <i></i>var.<i> occidentalis</i> Svenson, type from Santa Barbara, California (illustrated in H. L. Mason 1957; H. K. Svenson 1939, plate 539), applies to plants with culms only 2–6 cm, smooth or usually some prominently four-angled or finely to ca. eight-ridged, their bases often persistent, swollen, and cormlike (illustrated herein); distal leaf sheath summits mostly evident, often markedly inflated; achenes much less than two times longer than wide. This variety often grows in vernal pools. As here defined, it is known only from Arizona, California, and <i>Nevada</i>. Most of the specimens H. K. Svenson (1929) cited in the protologue and identified on herbarium specimens as <i>E. acicularis</i> <i></i>var.<i> occidentalis</i> are probably referable to typical <i>E. acicularis</i>.</p><!--
--><p><i>Eleocharis acicularis</i> var. porcata S. G. Smith (S. G. Smith 2001), type from Texas, applies to plants that are similar to <i>E. acicularis</i> <i></i>var.<i> occidentalis</i> except that their culms (cross section illustrated herein) reach 22 cm × 0.5 mm, some or all are prominently six- to twelve-ridged and mostly distinctly compressed, and their bases are not cormlike. This variety grows in mud and shallow water of marshes, ponds, and stream margins; it is known from Alberta, Arizona, Colorado, Illinois, Kansas, Louisiana, Nebraska, New Mexico, North Dakota, and Texas. Because of their compressed, prominently-ridged culms, robust plants of <i>E. acicularis</i> var. porcata, including a paratype of <i>E. wolfii</i>, are sometimes misidentified as <i>E. wolfii</i> (S. G. Smith 2001).</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Eleocharis acicularis
|authority=(Linnaeus) Roemer & Schultes
|rank=species
|parent rank=subgenus
|synonyms=Eleocharis acicularis var. gracilescens;Eleocharis acicularis var. occidentalis;Eleocharis acicularis var. porcata;Eleocharis acicularis var. submersa
|basionyms=Scirpus acicularis
|family=Cyperaceae
|phenology=Fruiting spring–fall.
|habitat=Bare, wet soil or in fresh (rarely brackish) lakes, ponds, vernal pools, meadows, springs, disturbed places
|elevation=0–3300 m
|distribution=Greenland;Alta.;B.C.;Man.;N.B.;Nfld. and Labr.;N.W.T.;N.S.;Nunavut;Ont.;P.E.I.;Que.;Sask.;Yukon;Alaska;Ariz.;Ark.;Calif.;Colo.;Conn.;Del.;D.C.;Ga.;Idaho;Ill.;Ind.;Iowa;Kans.;Ky.;La.;Maine;Md.;Mass.;Mich.;Minn.;Miss.;Mo.;Mont.;Nebr.;Nev.;N.H.;N.J.;N.Mex.;N.Y.;N.C.;N.Dak.;Ohio;Okla.;Oreg.;Pa.;R.I.;S.C.;S.Dak.;Tenn.;Tex.;Utah;Vt.;Va.;Wash.;W.Va.;Wis.;Wyo.;Mexico;Central America;South America (Ecuador);Eurasia;Australia (probably introduced).
|reference=None
|publication title=in J. J. Roemer et al., Syst. Veg.
|publication year=1817
|special status=W2;W1;Illustrated
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V23/V23_164.xml
|genus=Eleocharis
|subgenus=Eleocharis subg. Scirpidium
|species=Eleocharis acicularis
}}<!--

-->[[Category:Treatment]][[Category:Eleocharis subg. Scirpidium]]