Cyperus niger |
Cyperus digitatus |
|
---|---|---|
black flatsedge, brown cyperus |
finger flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, rhizomatous, coarse. |
Culms | solitary or close together, trigonous, 5–40(–95) cm, glabrous. |
trigonous, 50–150 cm × 2–15 mm, glabrous (rarely sparsely scabridulous on angles proximal to bracts). |
Leaves | (2–)3–7, broadly V-shaped, 3–20(–30) cm × 1.5–3 mm. |
inversely W-shaped, 40–100 cm × 5–15 mm. |
Inflorescences | spikes loosely to densely ovoid to hemispheric, 7–16 mm diam.; rachis 1–2 mm, or absent; rays 1–2, 3–45 mm; if rays absent, inflorescence sessile, dense, 6–20 mm diam; bracts 2–3, horizontal to reflexed downward, broadly V-shaped, 1–15 cm × 1–3 mm. |
spikes 1–4, cylindric, (2.5–)3.5–5 × 1.2–1.5 cm; rays 8–10, (1–)15–35 cm; 2d order rays 1–3 cm; bracts 8–12, ascending at 45–60°, (5–)20–80 cm × 3–15 mm; 2d order bracts 3–7 cm × 2–4 mm; rachilla persistent, wings 0.3 mm wide, at achene maturation adaxial edge of wing detaching from rachilla, base remaining firmly attached. |
Spikelets | (3–)5–25(–60), linear to oblong-linear, (3–)5–9 × 1.8–2.3 mm; floral scales 4–18, closely imbricate, chestnut brown, black, or brown, medially green or greenish brown, laterally ribless, medially 2(–3)-ribbed, distinctly 2-keeled basally, ovate to orbiculate, 1.5–2.1 × 1.4–2.2 mm, apex obtuse. |
35–65, slightly compressed, linear, ± quadrangular, 5–8 × 0.8–1.1 mm; floral scales deciduous, 12–16, appressed, marginally clear, laterally reddish along midrib, medially green, laterally 1–2-ribbed, medially strongly 5-ribbed, ovate, 1.6–1.8 × 1.1–1.3 mm, apex mucronulate. |
Flowers | stamens 2; anthers 0.6–0.8 mm, connectives not prolonged; styles 0.4–0.6 mm; stigmas 0.7–2.1 mm. |
anthers 0.4–0.5 mm, connective blunt, at most 0.1 mm; styles 0.8–1 mm; stigmas 0.4 mm. |
Achenes | brown, ellipsoid, 1.2–1.4 × 0.6–0.8 mm, network of ridges forming isodiametric or square cells, slightly stipitate, apex apiculate, surfaces minutely punctate. |
brown or whitish, sessile, ellipsoid, slightly wider at base, 0.9 × 0.4 mm, surfaces finely puncticulate. |
Cyperus niger |
Cyperus digitatus |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Swamps, ditches, wet pastures, seeps in montane forests | Wet pastures, stream banks |
Elevation | 0–1200 m (0–3900 ft) | 0–100 m (0–300 ft) |
Distribution |
AZ; CA; NM; OK; TX; Mexico; Central America; South America
|
FL; TX; Mexico; Central America; South America; Asia; Africa |
Discussion | Six varieties (Cyperus niger var. niger, var. castaneus, var. robustus, var. lorentizianus, var. intricate-ramosus, and var. pseudo-elegantulus) were recognized by G. Kükenthal (1935–1936). Based on field observations and measurements of hundreds of collections from Mexico, where the species is most plentiful, it does not seem possible to recognize any of the infraspecific taxa (G. C. Tucker 1983, 1994; G. C. Tucker and R. McVaugh 1993). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23. | FNA vol. 23, p. 173. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. diandrus var. castaneus, C. melanostachyus, C. niger var. castaneus | |
Name authority | Ruiz & Pavón: Fl. Peruv. 1: 47. (1798) | Roxburgh: Fl. Ind. 1: 209. (1820) |
Web links |