Cyperus niger |
Cyperus croceus |
|
---|---|---|
black flatsedge, brown cyperus |
Baldwin's flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs perennial, cespitose. |
Culms | solitary or close together, trigonous, 5–40(–95) cm, glabrous. |
trigonous, (4–)14–45 cm × 1–2 mm, glabrous. |
Leaves | (2–)3–7, broadly V-shaped, 3–20(–30) cm × 1.5–3 mm. |
yellow-green, flat, 18–44 cm × 3–4.5 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 densely to loosely globose to ovoid, 10–20 mm wide; rays (3–)5–9(–14), 1–15(–26) cm; rachis 3–6(–9) mm; bracts (4–)6–9(–11), horizontal to ascending at 45°, flat, 1–30 cm × 0.5–4 mm; rachilla deciduous, wings persistent, 0.3–0.5(–0.8) 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. |
(10–)30–50, oblong to lanceoloid, quadrangular to subterete, compressed, 4–8 × 1–1.3 mm; distal spikelet spreading or ascending; floral scales persistent, (1–)2–4(–6), appressed, whitish with red speckles, laterally 2–4-ribbed, ovate, 2.3–3.6 × 1.8–2.2 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. |
anthers 0.5 mm; styles 0.6–1.3 mm; stigmas 1.2–2.6 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. |
reddish brown to nearly black, sessile, oblong, ellipsoid, 2–2.4 × 0.4–0.5(–0.7) mm, apex ± truncate-emarginate, apiculate, surfaces puncticulate. |
Cyperus niger |
Cyperus croceus |
|
Phenology | Fruiting summer. | Fruiting summer–early fall. |
Habitat | Swamps, ditches, wet pastures, seeps in montane forests | Disturbed, sunny areas, coastal rocks, moist thickets |
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; DE; FL; GA; LA; MD; MO; MS; NC; NJ; OK; PA; SC; TN; TX; VA; WV; Mexico; Central America; West Indies; South America (Venezuela)
|
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 globulosus Aublet is a synonym of C. luzulae (Linnaeus) Rottbøll ex Retzius, which is a widespread neotropical species, and it has long been misapplied to Cyperus croceus (G. C. Tucker 1987). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 183. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. diandrus var. castaneus, C. melanostachyus, C. niger var. castaneus | C. baldwinii, C. cyclostachyus, C. echinatus var. multiflora, C. globulosus var. pseudofiliculmis, C. globulosus var. robustus, C. plankii, C. retrorsus var. robustus, Mariscus bracheilema, Mariscus brittonii |
Name authority | Ruiz & Pavón: Fl. Peruv. 1: 47. (1798) | Vahl: Enum. Pl. 2: 357. (1805) |
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