Cyperus niger |
Cyperus serotinus |
|
---|---|---|
black flatsedge, brown cyperus |
tidalmarsh flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, stoloniferous; stolons terminated by tubers. |
Culms | solitary or close together, trigonous, 5–40(–95) cm, glabrous. |
trigonous, 50–100 cm × 5–8 mm, glabrous. |
Leaves | (2–)3–7, broadly V-shaped, 3–20(–30) cm × 1.5–3 mm. |
3–6, V-shaped, 20–50 cm × 5–8(–10) 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 not appearing lateral, rays 5–8, 2–7(–12) cm; bracts 3–4, ± horizontal to ascending at 45°, V-shaped, 5–25 cm × 1.5–8 mm; spikes 1–4, ovoid, 2–4 × 2–3 cm; rachis 1–2.7 cm, smooth or hispidulous; rachilla persistent, wingless or with hyaline wings scarcely 0.1 mm wide. |
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. |
7–14, flattened, lanceoloid, 10–20 × 2–2.5 mm; floral scales 10–30, laterally dark brown to reddish brown, medially greenish, laterally 5–9-ribbed, ovate-deltate; anthers 3, 0.5 mm; styles 0.5 mm; stigmas 1.2–1.6 mm. |
Flowers | stamens 2; anthers 0.6–0.8 mm, connectives not prolonged; styles 0.4–0.6 mm; stigmas 0.7–2.1 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, sessile, ellipsoid, 1.4–1.6 × 1.4–1.5 mm, apex obtuse, apiculate. |
Cyperus niger |
Cyperus serotinus |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Swamps, ditches, wet pastures, seeps in montane forests | Tidal marshes |
Elevation | 0–1200 m (0–3900 ft) | 0 m (0 ft) |
Distribution |
AZ; CA; NM; OK; TX; Mexico; Central America; South America
|
DE; NJ; PA; Eurasia [Introduced in North America] |
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. 164. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Juncellus |
Sibling taxa | ||
Synonyms | C. diandrus var. castaneus, C. melanostachyus, C. niger var. castaneus | Chlorocyperus serotinus, Juncellus serotinus |
Name authority | Ruiz & Pavón: Fl. Peruv. 1: 47. (1798) | Rottbøll: Descr. Pl. Rar., 18. (1772) |
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