Cyperus niger |
Cyperus pseudovegetus |
|
---|---|---|
black flatsedge, brown cyperus |
marsh flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, cespitose; rhizomes upright, 5–8 mm diam., indurate. |
Culms | solitary or close together, trigonous, 5–40(–95) cm, glabrous. |
trigonous, 30–50(–80) cm × 1.8–2.5 mm, glabrous. |
Leaves | (2–)3–7, broadly V-shaped, 3–20(–30) cm × 1.5–3 mm. |
4–7(–10), V-shaped, (20–)40–60 cm × 4.5–8 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. |
heads dense, hemispheric, 7–15(–18) mm diam; or if rays absent, heads dense, irregularly lobate, 2–3.5 cm diam.; rays 3–6, 1–30 mm; 2d order rays infrequently present, to 5 mm; bracts (5–)10–15(–40), horizontal to ascending at 30(–45)°, V-shaped, 6–30(–40) cm × 5–8(–10) 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. |
40–100, greenish white, flattened, ovoid, 3.5–5 × 3–4 mm; floral scales (8–)12–16, uniformly light greenish to light brown, laterally 1-ribbed, medially indistinctly 3-ribbed, basally 2-keeled, oblong-spatulate, widest at or above median, 2–2.5 × (0.7–)1–1.2 mm, apex minutely mucronate, scabridulous, infrequently glabrous. |
Flowers | stamens 2; anthers 0.6–0.8 mm, connectives not prolonged; styles 0.4–0.6 mm; stigmas 0.7–2.1 mm. |
stamen 1; anthers oblong, 0.7–1 mm, connective apex subulate, prolonged 0.1–0.2 mm; styles thick, confluent with apex of, and persistent on, achene, 0.5–0.8 mm; stigmas 0.6–1 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, stipitate, linear, slightly curved, 1.2–1.4 × 0.2(–0.3) mm, base whitish, stipe spongy, 0.1–0.2 × 0.2 mm, apex acute, surfaces papillose. |
Cyperus niger |
Cyperus pseudovegetus |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Swamps, ditches, wet pastures, seeps in montane forests | Damp places |
Elevation | 0–1200 m (0–3900 ft) | 0–200 m (0–700 ft) |
Distribution |
AZ; CA; NM; OK; TX; Mexico; Central America; South America
|
AL; AR; DC; DE; FL; GA; IL; IN; KS; KY; LA; MA; MD; MO; NC; NJ; OK; SC; TN; TX; VA
|
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.) |
Cyperus pseudovegetus has been called “Cyperus vegetus Willd.” (M. L. Fernald 1950). The var. megalanthus Kükenthal of eastern Mexico and Central America recognized by M. F. Denton (1978b) is now considered a distinct species, C. megalanthus (Kükenthal) G. C. Tucker (see G. C. Tucker 1994). Cyperus pseudovegetus is introduced in Massachusetts. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 156. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. diandrus var. castaneus, C. melanostachyus, C. niger var. castaneus | |
Name authority | Ruiz & Pavón: Fl. Peruv. 1: 47. (1798) | Steudel: Syn. Pl. Glumac. 2: 24. (1855) |
Web links |