Difference between revisions of "Cyperus melanostachyus"
in A. von Humboldt et al., Nov. Gen. Sp. 1(fol.): 167.
1(qto.): 207. 1816.
GeoffLevin (talk | contribs) (Corrected illegitimate name Cyperus niger Riuz & Pavon to Cyperus melanostachyus Kunth, and made corresponding changes to publication data, synonyms, and discussion) |
GeoffLevin (talk | contribs) m (GeoffLevin moved page Cyperus niger to Cyperus melanostachyus: Correcting illegitimate name Cyperus niger to C. melanostachyus) |
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Revision as of 15:14, 15 November 2022
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
Ariz., Calif., N.Mex., Okla., Tex., Mexico, Central America, South America.
Discussion
Six varieties (var. niger, var. castaneus, var. robustus, var. lorentizianus, var. intricatoramosus, and var. pseudoelegantulus) were recognized by G. Kükenthal (1935–1936) under the illegitimate name Cyperus niger Ruiz and Pavon (1798), not Salisbury (1796). 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.