Cyperus virens |
Cyperus amabilis |
|
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green flatsedge |
foothill flatsedge |
|
Habit | Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. | Herbs, annual, cespitose. |
Culms | trigonous, (20–)60–70(–100) cm × 2.4–6.9 mm, scabrid on angles. |
1–10(–25), roundly trigonous, 3–12 cm × 0.3–0.8 mm, glabrous. |
Leaves | 4–12, flat to V-shaped, with readily visible cross ribs especially on abaxial surface, 20–50 cm × 3–14 mm. |
1–3–(4), 1–6 cm × 1(–1.5) 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. |
if rays absent heads single, dense, sessile, digitate, 5–20 × 10–30 mm, single heads 10–30(–50) mm; rays usually absent, if present 1–8 cm; 2d order rays infrequently present, 1–2 cm; bracts 3–6, erect to oblique, flat to V-shaped,(0.5–)2–10(–15) cm × 0.5–2 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. |
5–10(–20), linear to linear-lanceoloid, (5–)8–12(–35) × 1.6–2.3(–2.5) mm; floral scales (6–)16–30(–76), laterally glossy reddish brown to brown, medially greenish, sometimes also reddish or brownish, laterally ribless, medially strongly 3-ribbed, ovate-lanceolate, 1.9–2(–2.3) mm (including prominent excurved cusp of 0.3–0.5 mm) × 0.8–1.1 mm, apex truncate, emarginate, or cuspidate. |
Flowers | stamens 1–2; anthers 0.8–1.4 mm; styles 0.8–1 mm; stigmas 0.6–0.8 mm. |
stamens (1–)2–3; anthers ellipsoid, 0.3 mm, connectives not prolonged; styles 0.3–0.4 mm; stigmas 0.4–0.7 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, slightly stipitate, obovoid to oblong, 0.8–0.9 × 0.4–0.5 mm, apex abruptly apiculate, surfaces papillose. |
Cyperus virens |
Cyperus amabilis |
|
Phenology | Fruiting spring–fall. | Fruiting summer. |
Habitat | Wet pastures, marshes, roadside ditches | Seasonally wet, sandy soils |
Elevation | 500 m (1600 ft) | |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America
|
AZ; Mexico; Central America; South America; Asia; Africa |
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.) |
|
Source | FNA vol. 23, p. 153. | FNA vol. 23, p. 158. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. amabilis var. macrostachyus, C. aurantiacus, C. aureus, C. aureus var. aurantiacus, C. aureus var. macrostachyus, C. aureus var. oligostachyus, C. microstachyus, C. oligostachyus | |
Name authority | Michaux: Fl. Bor.-Amer. 1: 28. (1803) | Vahl: Enum. Pl. 2: 318. (1805) |
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