Cyperus polystachyos |
Cyperus subg. Pycreus |
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many-spike flatsedge |
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Habit | Herbs, perennial (annual?), cespitose. | |
Culms | trigonous or ± terete, (3–)20–45(–70) cm × (0.8–) 1.2–2 mm, glabrous. |
and leaves with Kranz (chlorocyperoid) anatomy. |
Leaves | (2–) 6–10(–16), flat to V-shaped, (2–) 10–30(–60) cm × 1–4 mm. |
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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. |
spikes; rachilla persistent, wingless or nearly so. |
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. |
borne in loosely spicate to ± digitate clusters; floral scales deciduous, 2-keeled or folded. |
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 (1–)2–3; pistils 2; stigmas 2. |
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. |
biconvex or ± cylindric, laterally compressed, edge borne toward rachilla. |
Cyperus polystachyos |
Cyperus subg. Pycreus |
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Phenology | Fruiting summer–early fall. | |
Habitat | Shores, ditches, swales between dunes | |
Elevation | 0–200 m (0–700 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
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Worldwide |
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.) |
Species ca. 100 (11 in the flora). Laterally compressed, biconvex achenes, a feature not occurring elsewhere in the family, distinguish Cyperus subg. Pycreus. The taxon has been treated as a genus in Flora Mesoamericana (C. D. Adams 1994), an idea that may have merit. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 160. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | C. brizaeus, C. polystachyos var. leptostachyus, Pycreus polystachyos | subg. Pycreus, C. section Pycreus |
Name authority | Rottbøll: Descr. Pl. Rar., 21. (1772) | (Palisot de Beauvois) J. Carey: Carices North. U. S., 517. (1847) |
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