Cyperus virens |
Cyperus elegans |
|
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green flatsedge |
royal flatsedge, sticky flatsedge |
|
Habit | Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. | Herbs, perennial, cespitose, shortly rhizomatous, coarse, viscous. |
Culms | trigonous, (20–)60–70(–100) cm × 2.4–6.9 mm, scabrid on angles. |
round to roundly trigonous, 15–80 cm × 2–4 mm, glabrous. |
Leaves | 4–12, flat to V-shaped, with readily visible cross ribs especially on abaxial surface, 20–50 cm × 3–14 mm. |
adaxial face concave, becoming trigonous apically, 15–75 cm × 1–4 mm, margins involute. |
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 ovoid, 10–20 mm wide; rays 3–8(–10), 0.5–12 cm; 2d order rays 0–3, 1–3 cm; bracts 3–7, horizontal to vertical, 2.5–5.5 cm × 1–4 mm, margins involute; 2d order bracts 0–3, 1–3 cm; rachilla persistent, 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. |
3–20(–30), beige to greenish or reddish brown, strongly compressed, oblong-ellipsoid to oblong-lanceoloid, 3–15 × 2.5–3.5 mm; floral scales deciduous, 6–22, laterally pale greenish white to stramineous or reddish brown, medially pale green to yellowish green, laterally 2-ribbed, medially 3–5-ribbed, broadly ovate, (2–)2.8–3.6 × 2.4–2.6 mm, apex with slightly excurved mucro 0.2–0.3 mm, apically scabrid. |
Flowers | stamens 1–2; anthers 0.8–1.4 mm; styles 0.8–1 mm; stigmas 0.6–0.8 mm. |
anthers 0.6–1.4 mm; styles 1.2–1.5 mm; stigmas 1–1.5(–3) 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. |
dark reddish brown to black, stipitate, obovoid, faces concave, flat or subtly convex, (1.4–)1.8–2 × 0.9–1 mm, base cuneate, stipe (sometimes absent) spongy, 0.1–0.2 × 0.2–0.4 mm, apex truncate, apiculate, surfaces coarsely papillose. |
Cyperus virens |
Cyperus elegans |
|
Phenology | Fruiting spring–fall. | Fruiting summer. |
Habitat | Wet pastures, marshes, roadside ditches | Ditches, damp pastures, pond shores, riverbanks |
Elevation | 0–500 m (0–1600 ft) | |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America
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FL; LA; NM; TX; Mexico; Central America; South America
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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. 172. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. trachynotus | |
Name authority | Michaux: Fl. Bor.-Amer. 1: 28. (1803) | Linnaeus: Sp. Pl. 1: 45. (1753) |
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