Cyperus hermaphroditus |
Cyperus virens |
|
---|---|---|
hermaphrodite flatsedge |
green flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. |
Culms | trigonous, (10–)30–80(–140) cm × (0.4–)1–3(–5) mm, glabrous. |
trigonous, (20–)60–70(–100) cm × 2.4–6.9 mm, scabrid on angles. |
Leaves | V-shaped or flanged V-shaped, (5–)15–70(–90) cm × (2–)4–10(–13) mm, glabrous. |
4–12, flat to V-shaped, with readily visible cross ribs especially on abaxial surface, 20–50 cm × 3–14 mm. |
Inflorescences | spikes 1(–5), rather densely ovoid or oblong-cylindric, (10–)25–45(–62) × 7–22 mm, 11–21 spikelets per 5 mm of rachis; rays (3–)5–10(–17), (1–)5–12(–24) cm; bracts (2–)4–8, ascending at 30–45°, V- or inversely W-shaped, (2–)8–40(–65) cm × (1–)2–8 mm; rachilla deciduous, wings 0.4–0.5 mm wide. |
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. |
Spikelets | (10–)50–150, oblong to linear, quadrangular, (3–)4–8(–18) × (0.8–)1–1.2(–1.6) mm; distal spikelet spreading or ascending; floral scales (1–) 3–8, pale greenish white to golden brown, deep brown, or reddish brown, medially usually green, weakly to strongly 3(–4)-ribbed laterally, 1–3-ribbed medially, ovate to elliptic, (2–)2.6–3.2(–4) × 1.2–2 mm, apex obtuse. |
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. |
Flowers | anthers (0.4–)0.6–1 mm; styles 0.4–1.6 mm; stigmas 1–1.5 mm. |
stamens 1–2; anthers 0.8–1.4 mm; styles 0.8–1 mm; stigmas 0.6–0.8 mm. |
Achenes | brown or reddish brown, sessile or nearly so, ellipsoid, 1.4–1.8(–2) × 0.6–0.8(–1) mm, apex acute to obtuse, slightly apiculate, surfaces puncticulate. |
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. |
Cyperus hermaphroditus |
Cyperus virens |
|
Phenology | Fruiting summer–fall. | Fruiting spring–fall. |
Habitat | Arroyos | Wet pastures, marshes, roadside ditches |
Elevation | 500–1200 m (1600–3900 ft) | |
Distribution |
AZ; TX; Mexico; South America; West Indies |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America
|
Discussion | An erroneous report of Cyperus hermaphroditus from Alabama was based on misidentification of C. thyrsiflorus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. 186. | FNA vol. 23, p. 153. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | Carex hermaphrodita, Mariscus hermaphroditus, Mariscus jacquinii | |
Name authority | (Jacquin) Standley: Contr. U.S. Natl. Herb. 18: 88. (1916) | Michaux: Fl. Bor.-Amer. 1: 28. (1803) |
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