Cyperus surinamensis |
Cyperus lecontei |
|
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tropical flatsedge |
Le Conte's flatsedge |
|
Habit | Herbs, annual or short-lived perennial, annuals cespitose; rhizomes absent. | Herbs, perennial, cespitose, rhizomatous, with stolons, lacking tubers. |
Culms | 2–6, trigonous, (10–)35–80 cm × 0.5–2(–4) mm, scabridulous with retrorse prickles (infrequently glabrous or rarely also with extrorse prickles). |
trigonous, 10–50 cm × 1–3 mm. |
Leaves | 3–9, V-shaped, (12–)25–45(–65) cm × 2–10 mm; blades and bracts without cross ribs. |
flat to V-shaped, 10–40 cm × 2–5 mm. |
Inflorescences | heads umbellate, 10–20(–30) mm diam.; rays 4–12, 1–6 cm, minutely scabridulous with retrorse prickles; 2d order rays often present, 1–2(–3) cm; 3d order rays rarely present, 0.5–1.5 cm; bracts 3–8, approximately horizontal to ascending at 30°, V-shaped to flat, 2–15(–34) cm × 1–4(–5) mm. |
heads digitate, 10–40 mm diam.; rays 5–12, 1–12 cm; 2d order rays 1–3 cm; bracts 3–5, horizontal, flat to V-shaped, 1–15 cm × 1–2 mm. |
Spikelets | (6–)15–40(–65), greenish white, linear to linear-oblong, (3–)4–12(–15) × 1.5–2.5 mm; floral scales 10–50(–65), laterally pale yellow, light brown, or reddish brown, 2-keeled, medially 3-ribbed, lanceolate, 1–1.5 × 0.8–0.9 mm, distinctly reticulate, often scabridulous near apex. |
(1–)2–4(–6), oblong to linear, compressed, 5–25 × 2.8–3.6 mm; floral scales 20–60, stramineous or reddish green, laterally weakly 3-ribbed, ovate-elliptic, 2.5–3 × 1–1.8 mm. |
Flowers | stamen 1; anthers 0.5 mm; styles 0.8–1.1 mm; stigmas 0.5 mm. |
stamens 3; anthers 1–1.3 mm; styles 0.6 mm; stigmas 1.5 mm. |
Achenes | brown to reddish brown, slightly stipitate, narrowly ellipsoid, 0.7–0.9 × 0.2–0.4 mm, apex apiculate, surfaces papillate or obscurely reticulate to rugulose. |
reddish brown, sessile, ovoid, 0.7–0.8 × 0.4–0.5 mm, apex obtuse, apiculate or not, surfaces glabrous. |
Cyperus surinamensis |
Cyperus lecontei |
|
Phenology | Fruiting late spring–early fall. | Fruiting summer. |
Habitat | Moist sunny areas with disturbed soils | Emergent shorelines |
Elevation | 0–200 m (0–700 ft) | 0–100(–300) m (0–300(–1000) ft) |
Distribution |
AL; AR; FL; GA; KS; LA; MS; OK; SC; TN; TX; Mexico; Central America; South America
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AL; FL; LA; MS; NC; SC
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Discussion | Cyperus surinamensis is distinguished readily from all other species of the genus in the New World by the usual presence of retrorse prickles on the culms and rays. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 153. | FNA vol. 23, p. 151. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. dentatus var. multiradiatus, C. multiradiatus | |
Name authority | Rottbøll: Descr. Pl. Rar., 20. (1772) | Torrey ex Steudel: Syn. Pl. Glumac. 2: 21. (1855) |
Web links |