Cyperus niger

Ruiz & Pavón

Fl. Peruv. 1: 47. 1798.

Illustrated
Synonyms: Cyperus diandrus var. castaneus S. Watson Cyperus melanostachyus Kunth Cyperus niger var. castaneus (S. Watson) Kükenthal
Treatment appears in FNA Volume 23. Mentioned on page 161.

Herbs, perennial, rhizomatous. Culms solitary or close together, trigonous, 5–40(–95) cm, glabrous. Leaves (2–)3–7, broadly V-shaped, 3–20(–30) cm × 1.5–3 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. 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. 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.


Phenology: Fruiting summer.
Habitat: Swamps, ditches, wet pastures, seeps in montane forests
Elevation: 0–1200 m

Distribution

V23 254-distribution-map.jpg

Ariz., Calif., N.Mex., Okla., Tex., Mexico, Central America, South 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).

Selected References

None.

Lower Taxa

None.
... more about "Cyperus niger"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Ruiz & Pavón +
Undefined subg. Pycreus +
Ariz. +, Calif. +, N.Mex. +, Okla. +, Tex. +, Mexico +, Central America +  and South America. +
0–1200 m +
Swamps, ditches, wet pastures, seeps in montane forests +
Fruiting summer. +
Illustrated +
Cyperus diandrus var. castaneus +, Cyperus melanostachyus +  and Cyperus niger var. castaneus +
Cyperus niger +
Cyperus subg. Pycreus +
species +