Cyperus virens |
Cyperus fendlerianus |
|
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green flatsedge |
Fendler flatsedge, Fendler's flatsedge, Fendler's nutgrass, Fendler's sedge |
|
Habit | Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. | Herbs, perennial, rhizomatous. |
Culms | trigonous, (20–)60–70(–100) cm × 2.4–6.9 mm, scabrid on angles. |
trigonous, (7–)20–70(–85) cm × (0.5–)1–1.8(–2.6) mm, glabrous or sparsely to densely scabridulous on surfaces or on angles immediately proximal to inflorescence in distal 3–6 cm. |
Leaves | 4–12, flat to V-shaped, with readily visible cross ribs especially on abaxial surface, 20–50 cm × 3–14 mm. |
2–3, flat to V-shaped, (12–)20–40(–55) cm × (2–)3–5(–7) 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. |
spikes (1–)3–4(–6), largest erect, others at base of central spike, erect spike sessile, loosely to densely cylindric to ovoid-cylindric, (12–)18–30 × (6–)12–20 mm, remaining spikes 1/2 as large; rays absent; bracts (2–)3–6(–10), ± horizontal to reflexed parallel to culm, (2–)6–16(–25) cm × (1.5–)2–4(–7) mm; rachilla ± deciduous, wingless. |
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. |
(8–)15–30, spreading to ascending-appressed, oblong-lanceoloid, quadrangular, slightly compressed, 5–8(–10) × (2–)2.4–3.4(–4.2) mm; floral scales (2–)4–6(–8), yellowish, reddish, or greenish brown, medially greenish, straight to excurved, laterally (2–)3–4(–5)-ribbed, medially (1–)3–(–5)-ribbed, ovate-orbiculate, 2.4–2.8(–3.4) × 2.4–2.8(–3.4) mm, apex obtuse, mucronate to cuspidate, stout, (0.1–)0.3–0.6 mm, medially glabrous. |
Flowers | stamens 1–2; anthers 0.8–1.4 mm; styles 0.8–1 mm; stigmas 0.6–0.8 mm. |
anthers 0.4–0.8 mm; styles 0.7–1.3 mm; stigmas 0.7–1.2 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. |
finely reticulate, brown to reddish brown, ± stipelike, obovoid, 1.6–1.9 × 1.1–1.4(–1.6) mm, base attenuate to cuneate, 0.1–0.2 × 0.2 mm, apex obtuse, apiculate, surfaces glabrous. |
Cyperus virens |
Cyperus fendlerianus |
|
Phenology | Fruiting spring–fall. | Fruiting summer. |
Habitat | Wet pastures, marshes, roadside ditches | Clearings in montane forests |
Elevation | 500–1800 m (1600–5900 ft) | |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America
|
AZ; CO; NM; TX; WY; Mexico
|
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.) |
Hybridization between Cyperus fendlerianus and C. sphaerolepis occurs occasionally in the southwestern United States and northern Mexico (B. G. Marcks 1972). The unnamed hybrid appears to be fully fertile and can be recognized by morphologic intermediacy. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 153. | FNA vol. 23, p. 177. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | Chlorocyperus fendlerianus | |
Name authority | Michaux: Fl. Bor.-Amer. 1: 28. (1803) | Boeckeler: Linnaea 35: 520. (1868) |
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