Cyperus niger |
Cyperus grayoides |
|
---|---|---|
black flatsedge, brown cyperus |
Illinois flatsedge, Mohlenbrock's sedge, umbrella sedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, cespitose, rhizomatous, tuberlike. |
Culms | solitary or close together, trigonous, 5–40(–95) cm, glabrous. |
trigonous, 5–35 cm × 0.7–1.2 mm, glabrous. |
Leaves | (2–)3–7, broadly V-shaped, 3–20(–30) cm × 1.5–3 mm. |
V-shaped, 5–25 cm × 1.5–3.5 mm, slightly scabridulous on abaxial margins, midrib. |
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 loosely ± globose, 15–25 mm wide; rays 1–10 cm; rachis 1–4 mm; bracts 3–7, ascending, V-shaped, 3–20 cm × 1–3 mm; rachilla deciduous, wingless. |
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. |
3–24, compressed, oblong-lanceoloid, 4–12 × 2.5–3.2 mm; floral scales deciduous, 3–9, pale reddish brown, ovate, laterally 3–5-ribbed, 2.5–3 × 2–2.4 mm, apex acute to obtuse. |
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 1–1.2 mm; styles 0.4–0.6 mm; stigmas 1–2 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. |
dark brown, ± stipitate, ellipsoid, 2–2.4 × 0.9–1.2 mm, apex obtuse, apiculate, surfaces glabrous, puncticulate, or papillose. |
2n | = 166. |
|
Cyperus niger |
Cyperus grayoides |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Swamps, ditches, wet pastures, seeps in montane forests | Sand prairies, waste places, fallow fields |
Elevation | 0–1200 m (0–3900 ft) | 100–300 m (300–1000 ft) |
Distribution |
AZ; CA; NM; OK; TX; Mexico; Central America; South America
|
AR; IL; LA; MO; TX
|
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.) |
Of conservation concern. Cyperus grayoides is in the Center for Plant Conservation’s National Collection of Endangered Plant’s. See frontispiece. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23. |
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) | Mohlenbrock: Brittonia 11: 255, fig. 1. (1959) |
Web links |