View source for Eleocharis compressa

{{Treatment/ID
|accepted_name=Eleocharis compressa
|accepted_authority=Sullivant
|publications={{Treatment/Publication
|title=Amer. J. Sci. Arts
|place=42: 50. 1842
|year=1842
}}
|special_status={{Treatment/ID/Special_status
|code=F
|label=Illustrated
}}{{Treatment/ID/Special_status
|code=E
|label=Endemic
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Eleocharis elliptica var. compressa
|authority=(Sullivant) Drepalik & Mohlenbrock
|rank=variety
}}
|hierarchy=Cyperaceae;Eleocharis;Eleocharis subg. Eleocharis;Eleocharis sect. Eleocharis;Eleocharis (sect. Eleocharis) ser. Eleocharis;Eleocharis compressa
|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. Eleocharis]]</div><div class="higher-taxon"><small>section</small>[[Eleocharis sect. Eleocharis]]</div><div class="higher-taxon"><small>series</small>[[Eleocharis (sect. Eleocharis) ser. Eleocharis]]</div><div class="higher-taxon"><small>species</small>[[Eleocharis compressa]]</div></div>
|volume=Volume 23
|mention_page=page 83
|treatment_page=
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>perennial, mat-forming; rhizomes evident, short to rather long, 2–3 mm thick, firm, cortex persistent, internodes very short to 2 mm, scales often decaying to coarse fibers, 5–12 mm, papery. <b>Culms</b> subterete to greatly compressed, to 5 times as wide as thick, often with 2–12 ridges, 8–45 cm × (0.2–)0.5–1.8 mm, firm to hard, spongy. <b>Leaves</b>: distal leaf sheaths persistent, not splitting, proximally red, distally green to stramineous, papery, apex usually red-brown, broadly obtuse to subtruncate, callose, tooth absent. <b>Spikelets</b> ovoid, 4–8 × 2–4 mm, apex acute; proximal scale clasping 3/4 of culm to amplexicaulous, entire; subproximal scale empty or with flower; floral scales spreading in fruit, 20–60, 6 per mm of rachilla, medium brown to very dark brown, sometimes stramineous or colorless, midrib region often paler, ovate, 2–3(–4) × 1–1.5 mm, apex acute to acuminate, the apical colorless hyaline region mostly longer than wide and 0.6–1.2 mm, in proximal part of spikelet 2-fid to shallowly cut, rarely entire, in distal part often entire, carinate in distal part of spikelet. <b>Flowers</b>: perianth bristles 0–5, stramineous, length variable, to equaling achene, obscurely to clearly retrorsely spinulose; stamens 3; anthers yellow- to orange-brown, 0.7–2 mm; styles 3-fid or some 2-fid. <b>Achenes</b> falling with scales or some persistent, yellow-brown or dark brown, obovoid to obpyriform, nearly equilaterally to compressed-trigonous or usually some biconvex, angles evident or obscure, 0.8–1.1 × 0.6–0.8 mm, neck very short, finely rugulose and sometimes finely (or coarsely) cancellate at 10–20X with 14–20 blunt horizontal ridges in a vertical series. <b>Tubercles</b> brown (to whitish), pyramidal, usually depressed, often rudimentary, 0.15–0.3 × 0.2–0.35 mm.</span><!--

-->{{Treatment/Body
|distribution=B.C.;Man.;Ont.;Que.;Sask.;Ala.;Ark.;Colo.;D.C.;Ill.;Ind.;Iowa;Kans.;Ky.;Md.;Mich.;Minn.;Miss.;Mo.;N.Dak.;N.Mex.;N.Y.;Nebr.;Ohio;Okla.;Pa.;S.Dak.;Tenn.;Tex.;Va.;W.Va.;Wis.
|discussion=<p>Varieties 2 (2 in the flora).</p><!--
--><p><i>Eleocharis compressa</i> is extremely variable. After <i>E. bifida</i> and <i>E. occulta</i> are segregated from <i>E. compressa</i> (type from Ohio) and E. acutisquamata (type from Texas), the remaining plants intergrade completely and are best treated as varieties of <i>E. compressa</i> (S. G. Smith 2001). Because some plants of <i>E. compressa</i> approach <i>E. elliptica</i> some authors have treated <i>E. compressa</i> as a synonym of <i>E. elliptica</i>. Putative <i>E. compressa</i> × <i>E. erythropoda</i> hybrids from southeastern Ontario have been described (P. M. Catling 1994), and I have observed similar putative hybrids in the field in southeastern Wisconsin. Introgression from <i>E. erythropoda</i> is suggested by the presence in many plants of <i>E. compressa</i> of some 2-fid styles and biconvex achenes and some or rarely all entire floral scales, including the type. Some collections of <i>E. compressa</i> from the District of Columbia region and Tennessee have distinctly cancellate achenes as is common in <i>E. tenuis </i>var.<i> verrucosa</i>. The earlier name <i>E. acuminata</i> (Muhlenberg) Nees, name confused (H. K. Svenson 1932), is often given as a synonym of <i>E. compressa</i> (S. G. Smith 2001).</p><!--
--><p>Both 2n = 24 and 2n = 26 cytotypes for <i>E. compressa</i> from south-central United States have been reported (L. J. Harms 1972). Fertile artificial hybrids between these two cytotypes were also reported, as well as artificial <i>E. compressa</i> (2n = 36) × <i>E. elliptica</i> (2n = 38) hybrids with meiotic pairing and pollen stainability more than 90 percent. I have not seen voucher specimens for those artificial hybrids or for any of the published chromosone number reports for <i>E. compressa</i>, except for a count of 2n = 24 (presumably made by L. J. Harms) that is given on a herbarium specimen label of <i>E. compressa </i>var.<i> acutisquamata</i> from Kansas (S. G. Smith 2001).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Culms compressed, 2–5 times as wide as thick, 0.5–1.8 mm wide.
|[[Eleocharis compressa var. compressa|Eleocharis compressa var. compressa]]
|-id=key-0-1
|1
|Culms subterete to slightly compressed, not more than 2 times as wide as thick, (0.2–)0.5–1 mm wide.
|[[Eleocharis compressa var. acutisquamata|Eleocharis compressa var. acutisquamata]]
|}
</div></div><!--

-->{{#Taxon:
name=Eleocharis compressa
|authority=Sullivant
|rank=species
|parent rank=series
|synonyms=Eleocharis elliptica var. compressa
|basionyms=
|family=Cyperaceae
|distribution=B.C.;Man.;Ont.;Que.;Sask.;Ala.;Ark.;Colo.;D.C.;Ill.;Ind.;Iowa;Kans.;Ky.;Md.;Mich.;Minn.;Miss.;Mo.;N.Dak.;N.Mex.;N.Y.;Nebr.;Ohio;Okla.;Pa.;S.Dak.;Tenn.;Tex.;Va.;W.Va.;Wis.
|reference=None
|publication title=Amer. J. Sci. Arts
|publication year=1842
|special status=Illustrated;Endemic
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V23/V23_113.xml
|genus=Eleocharis
|subgenus=Eleocharis subg. Eleocharis
|section=Eleocharis sect. Eleocharis
|series=Eleocharis (sect. Eleocharis) ser. Eleocharis
|species=Eleocharis compressa
}}<!--

-->[[Category:Treatment]][[Category:Eleocharis (sect. Eleocharis) ser. Eleocharis]]