View source for Cyperus rotundus

{{Treatment/ID
|accepted_name=Cyperus rotundus
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=1: 45. 1753
|year=1753
}}
|common_names=Purple nut-sedge;coco-grass
|basionyms=
|synonyms=
|hierarchy=Cyperaceae;Cyperus;Cyperus subg. Cyperus;Cyperus rotundus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Cyperaceae]]</div><div class="higher-taxon"><small>genus</small>[[Cyperus]]</div><div class="higher-taxon"><small>subgenus</small>[[Cyperus subg. Cyperus]]</div><div class="higher-taxon"><small>species</small>[[Cyperus rotundus]]</div></div>
|volume=Volume 23
|mention_page=page 146, 168, 170
|treatment_page=page 169
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Herbs,</b> perennial, stoloniferous; stolons (2–)5–12 cm × 1–2 mm, bearing tubers 3–8(–12) mm diam., wiry, springy when dried, indurate. <b>Culms</b> trigonous, 10–35(–40) cm × 0.7–3.4 mm, basally indurate, glabrous. <b>Leaves</b> V-shaped to flanged V-shaped, 5–30 cm × 2–6 mm. <b>Inflorescences</b>: spikes 1(–3), broadly ellipsoid, (12–)15–25(–30) × (12–)20–30(–50) mm, rays (3–)4–6(–7), 0.2–10 cm;, bracts (2–)3–5, horizontal to ascending at 45°, V-shaped to flanged V-shaped, 0.5–10 cm × 0.5–4 mm, rachilla persistent, wings 0.5–1 mm wide. <b>Spikelets</b> (2–)3–7(–12), compressed, linear, 4–40 × 1.3–1.8 mm, floral scales persistent, 6–36(–42), spreading or appressed, purple to reddish brown, with narrow clear border and green midrib, 7–9-ribbed, ovate, (1.8–)2.6–3.4 × 2.2–3 mm, apex obtuse. <b>Flowers</b>: anthers 1–2.5 mm, styles 1.3–3.5 mm, stigmas (1.8–)2–3.3 mm. <b>Achenes</b> black, sessile, ellipsoid, abaxial face convex, adaxial face concave, 1.4–1.7(–1.9) × 0.8–1 mm, apex obtuse, surfaces puncticulate.</span><!--

-->{{Treatment/Body
|phenology=Fruiting summer–fall.
|habitat=Croplands, disturbed soils usually
|elevation=0–400 m
|distribution=Ala.;Ariz.;Ark.;Calif.;Fla.;Ga.;La.;Miss.;Mo.;N.Mex.;N.C.;S.C.;Tenn.;Tex.;Va.;Mexico;Central America;South America;Asia;Africa;Australia.
|discussion=<p><i>Cyperus rotundus</i> is documented in Connecticut, Delaware, New York, and Pennsylvania; there is no evidence of persistent populations.</p><!--
--><p><i>Cyperus esculentus</i> and <i>C. rotundus</i> are the only two species of subg. <i>Cyperus</i> in the New World that produce tuberiferous stolons. The two species also have persistent floral scales and persistent rachillas, a combination of characteristics not found in any other New World species of <i>Cyperus</i>.</p><!--
--><p><i>Cyperus rotundus</i> is distinguished from other species of the genus in the New World by its open spikes composed of linear reddish spikelets borne on a conspicuous slender rachis. <i>Cyperus rotundus</i> is usually acknowledged to be the world’s worst weed (cf. G. C. Tucker 1987). In the United States, it does not grow north of the mean 1°C January isotherm. <i>Cyperus esculentus</i> (preceding species) is a serious weed in much of the world, especially in cooler regions where the more tropical <i>C. rotundus</i> does not grow. <i>Cyperus esculentus</i> is able to tolerate lower air temperatures (as low as -18°C). The two species apparently differ also in their thermal optima for growth.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Cyperus rotundus
|author=
|authority=Linnaeus
|rank=species
|parent rank=subgenus
|synonyms=
|basionyms=
|family=Cyperaceae
|phenology=Fruiting summer–fall.
|habitat=Croplands, disturbed soils usually
|elevation=0–400 m
|distribution=Ala.;Ariz.;Ark.;Calif.;Fla.;Ga.;La.;Miss.;Mo.;N.Mex.;N.C.;S.C.;Tenn.;Tex.;Va.;Mexico;Central America;South America;Asia;Africa;Australia.
|reference=None
|publication title=Sp. Pl.
|publication year=1753
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f6b125a955440c0872999024f038d74684f65921/coarse_grained_fna_xml/V23/V23_277.xml
|genus=Cyperus
|subgenus=Cyperus subg. Cyperus
|species=Cyperus rotundus
}}<!--

-->[[Category:Treatment]][[Category:Cyperus subg. Cyperus]]