Cyperus polystachyos |
Cyperus sanguinolentus |
|
---|---|---|
many-spike flatsedge |
purpleglume flatsedge |
|
Habit | Herbs, perennial (annual?), cespitose. | Herbs, perennial; rhizomes ± horizontal, to 12 cm × 0.8–1.2 mm. |
Culms | trigonous or ± terete, (3–)20–45(–70) cm × (0.8–) 1.2–2 mm, glabrous. |
± terete to roundly trigonous, 3–25(–60) cm × 0.3–2 mm, glabrous. |
Leaves | (2–) 6–10(–16), flat to V-shaped, (2–) 10–30(–60) cm × 1–4 mm. |
1–3, V-shaped, 1–8(–15) cm × 1–2 mm. |
Inflorescences | spike 1, loosely ovoid to densely turbinate, 12–40 × 10–25 mm; rachis 3–10 mm; rays 1–8(–12), 0.5–3(–6) cm; 2d order rays absent; if rays absent, inflorescence single dense cluster of spikelets, 12–40 mm diam.; bracts (3–)4–6(–7), horizontal to ascending at 45°, flanged V-shaped, (2–)5–15(–23) cm × 1–4 mm. |
spike 1, loosely ovoid, 7–14 × 8–20 mm; rays (0–)1–4, to 2(–3) cm; bracts 2–4, horizontal to ascending at 30(–45)°, V-shaped to flat, 1–8(–18) cm × 0.5–1.5(–2) mm. |
Spikelets | (5–)15–30(–40), spreading to appressed-ascending, linear-lanceoloid to linear, compressed, 8–18(–40) × (1–)1.3–1.6(–2) mm; floral scales (8–)12–25(–66), laterally stramineous to light brown, medially green, laterally ribless, medially 3–5-ribbed, oblong, (1.5–)1.8–2.4 × (1–)1.2–1.4 mm, apex acute to ± acute, mucronate. |
3–5(–14), oblong to linear-lanceoloid, 8–18 × 2–2.6(–3) mm; floral scales (6–)10–26(–32), laterally clear to light brown, sometimes with purplish margins, medially light brown, 2-keeled, laterally ribless, medially 2–3-ribbed, oblong to ovate, 1.9–2.2(–2.7) × 1.8–2.3 mm, apex obtuse. |
Flowers | stamens 2; anthers (0.4–)0.5–0.8 mm, connective not prolonged; styles 0.6–1(–1.4) mm; stigmas (1–)1.4–2 mm. |
stamens 3; anthers ellipsoid, 0.3–0.6 mm, connective not prolonged; styles 0.6–1 mm; stigmas 1–1.5 mm. |
Achenes | light to dark brown, oblong, (0.8–)0.9–1.1(–1.2) × 0.4–0.5(–0.6) mm, base cuneate to ± stipelike, apex truncate, apiculate, surfaces punctate to minutely punctate with raised cells. |
brown, ± stipitate, obovoid to ovoid, 1–1.4 × 0.6–0.8 mm, apex truncate, apiculate, surfaces minutely punctate. |
Cyperus polystachyos |
Cyperus sanguinolentus |
|
Phenology | Fruiting summer–early fall. | Fruiting late summer–fall. |
Habitat | Shores, ditches, swales between dunes | Emergent shorelines, ditches |
Elevation | 0–200 m (0–700 ft) | 20 m (100 ft) |
Distribution |
AL; DC; DE; FL; GA; KY; LA; MA; MD; ME; MS; NC; NJ; NY; OK; PA; SC; TX; VA; WV; Mexico; Central America; South America; Asia; Africa
|
AL; GA; LA; MS; Asia; Africa [Introduced in North America] |
Discussion | Cyperus polystachyos is polymorphic. Adequate understanding of the infraspecific variations of C. polystachyos requires a worldwide examination, which is beyond the scope of this study. The segregates, C. fugax and C. filicinus, are recognized here; they have been usually accepted by recent workers (e.g., M. L. Fernald 1950; H. A. Gleason and A. Cronquist 1991). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus sanguinolentus is the only rhizomatous, distigmatic Cyperus in the eastern United States. An early collection from Louisiana was described as C. louisianensis, supposedly endemic. Recent field work and morphometric studies convincingly showed it to be an introduction of the Asian C. sanguinolentus) (J. R. Carter and C. T. Bryson 2001. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 160. | FNA vol. 23, p. 161. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Pycreus |
Sibling taxa | ||
Synonyms | C. brizaeus, C. polystachyos var. leptostachyus, Pycreus polystachyos | C. louisianensis, Pycreus sanguinolentus |
Name authority | Rottbøll: Descr. Pl. Rar., 21. (1772) | Vahl: Enum. Pl. 2: 351. (1805) |
Web links |