Cyperus polystachyos |
Cyperus compressus |
|
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many-spike flatsedge |
annual sedge, poorland flatsedge |
|
Habit | Herbs, perennial (annual?), cespitose. | Herbs, annual, cespitose with fibrous roots. |
Culms | trigonous or ± terete, (3–)20–45(–70) cm × (0.8–) 1.2–2 mm, glabrous. |
trigonous, (2–)6–15(–35) cm × (0.3–)1–1.8 mm, glabrous. |
Leaves | (2–) 6–10(–16), flat to V-shaped, (2–) 10–30(–60) cm × 1–4 mm. |
1–5, flat to V-shaped, (1–)5–15(–22) cm × (0.5–)1.5–3 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. |
spikes ± digitate, ± globose, 7–40 × 10–20 mm; rays (0–)1–6, 2–12 cm; if absent, inflorescence a sessile cluster of (1–)3–10 spikelets; rachis 2–5 mm; bracts (1–)4–5(–6), ascending, V-shaped, 1–15(–20) cm × 0.5–3.5 mm; rachilla persistent, wingless. |
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. |
(1–)3–12(–16), greenish white, linear to linear-lanceoloid, compressed-quadrangular, 6–34(–40) × 2–3(–3.6) mm; floral scales deciduous, (8–)16–36(–42), spreading, laterally whitish, greenish, or pale brownish, medially green, weakly 7–9-ribbed, laterally weakly 1–2-ribbed, most ribs medial, ovate, (2.4–)2.6–3 × (1.9–)2–2.4(–2.5) mm, apex acute to ± acute, cuspidate tip (0.3–)0.5–0.7(–0.8) mm. |
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. |
anthers 0.6–0.7 mm; styles 0.9–1.3 mm; stigmas 0.5–0.8 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 to sessile, obovoid, (1–)1.2–1.4(–1.5) × 0.9–1(–1.1) mm, apex obtuse to emarginate, surfaces very finely puncticulate. |
Cyperus polystachyos |
Cyperus compressus |
|
Phenology | Fruiting summer–early fall. | Fruiting summer–early fall. |
Habitat | Shores, ditches, swales between dunes | Various disturbed soils |
Elevation | 0–200 m (0–700 ft) | 0–900 m (0–3000 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; AR; DE; FL; GA; IL; LA; MD; MO; MS; NC; NY; OH; PA; SC; TX; VA; Mexico; Central America; South America; Asia; Africa
|
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.) |
|
Source | FNA vol. 23, p. 160. | FNA vol. 23, p. 171. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. brizaeus, C. polystachyos var. leptostachyus, Pycreus polystachyos | C. compressus var. pectiniformis, C. pectinatus, C. pectiniformis |
Name authority | Rottbøll: Descr. Pl. Rar., 21. (1772) | Linnaeus: Sp. Pl. 1: 46. (1753) |
Web links |