Cyperus virens |
Cyperus pseudovegetus |
|
---|---|---|
green flatsedge |
marsh flatsedge |
|
Habit | Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. | Herbs, perennial, cespitose; rhizomes upright, 5–8 mm diam., indurate. |
Culms | trigonous, (20–)60–70(–100) cm × 2.4–6.9 mm, scabrid on angles. |
trigonous, 30–50(–80) cm × 1.8–2.5 mm, glabrous. |
Leaves | 4–12, flat to V-shaped, with readily visible cross ribs especially on abaxial surface, 20–50 cm × 3–14 mm. |
4–7(–10), V-shaped, (20–)40–60 cm × 4.5–8 mm. |
Inflorescences | heads digitate to hemispheric, 1–3.5 cm diam.; rays 6–12, 1–9(–14) cm; 2d order rays often present, (0.5–)1–3 cm; 3d order rays occasionally present, 5–12 mm; bracts 4–8, horizontal to ascending at 30°, with prominent cross ribs,V-shaped, (1.5–)3–50(–75) cm × 0.5–13 mm; 2d order bracts 3–10 × 1–2 mm. |
heads dense, hemispheric, 7–15(–18) mm diam; or if rays absent, heads dense, irregularly lobate, 2–3.5 cm diam.; rays 3–6, 1–30 mm; 2d order rays infrequently present, to 5 mm; bracts (5–)10–15(–40), horizontal to ascending at 30(–45)°, V-shaped, 6–30(–40) cm × 5–8(–10) mm. |
Spikelets | 10–40(–50), oblong to linear-lanceoloid, 5–18 × 2–3.2 mm; floral scales 10–40, pale grayish brown, or greenish, proximally greenish or brownish, oblanceolate, 2-keeled, weakly to distinctly 1-ribbed, proximal half 2-ribbed, (1.3–)1.5–2(–2.4) × 0.9–1.4 mm, apex acute (sometimes mucronulate), apically glabrous, occasionally scabridulous. |
40–100, greenish white, flattened, ovoid, 3.5–5 × 3–4 mm; floral scales (8–)12–16, uniformly light greenish to light brown, laterally 1-ribbed, medially indistinctly 3-ribbed, basally 2-keeled, oblong-spatulate, widest at or above median, 2–2.5 × (0.7–)1–1.2 mm, apex minutely mucronate, scabridulous, infrequently glabrous. |
Flowers | stamens 1–2; anthers 0.8–1.4 mm; styles 0.8–1 mm; stigmas 0.6–0.8 mm. |
stamen 1; anthers oblong, 0.7–1 mm, connective apex subulate, prolonged 0.1–0.2 mm; styles thick, confluent with apex of, and persistent on, achene, 0.5–0.8 mm; stigmas 0.6–1 mm. |
Achenes | brown, slightly to distinctly stipitate, ellipsoid (2.7–4.1 times as long as wide), (0.9–)1.2–1.5 × 0.3–0.4 mm, apical beak 0.1–0.5 mm, surfaces glabrous. |
brown, stipitate, linear, slightly curved, 1.2–1.4 × 0.2(–0.3) mm, base whitish, stipe spongy, 0.1–0.2 × 0.2 mm, apex acute, surfaces papillose. |
Cyperus virens |
Cyperus pseudovegetus |
|
Phenology | Fruiting spring–fall. | Fruiting summer. |
Habitat | Wet pastures, marshes, roadside ditches | Damp places |
Elevation | 0–200 m (0–700 ft) | |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America
|
AL; AR; DC; DE; FL; GA; IL; IN; KS; KY; LA; MA; MD; MO; NC; NJ; OK; SC; TN; TX; VA
|
Discussion | Cyperus virens was found as waif in California in the 1800s (M. F. Denton 1978b; G. C. Tucker 1993b). Cyperus virens is readily distinguished from other species of subg. Pycnostachys by its trigonous culms, scabrid angles, and leaves and inflorescence bracts conspicuously septate by numerous cross ribs between the main ribs. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus pseudovegetus has been called “Cyperus vegetus Willd.” (M. L. Fernald 1950). The var. megalanthus Kükenthal of eastern Mexico and Central America recognized by M. F. Denton (1978b) is now considered a distinct species, C. megalanthus (Kükenthal) G. C. Tucker (see G. C. Tucker 1994). Cyperus pseudovegetus is introduced in Massachusetts. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 153. | FNA vol. 23, p. 156. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Name authority | Michaux: Fl. Bor.-Amer. 1: 28. (1803) | Steudel: Syn. Pl. Glumac. 2: 24. (1855) |
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