Cyperus polystachyos |
Cyperus gracilis |
|
---|---|---|
many-spike flatsedge |
slimjim flatsedge |
|
Habit | Herbs, perennial (annual?), cespitose. | Herbs, annual or perennial. |
Culms | trigonous or ± terete, (3–)20–45(–70) cm × (0.8–) 1.2–2 mm, glabrous. |
weak, often arching, basally culmlike, weakly 4(–5)-angled, 10–30 cm × 0.2–0.4 mm, glabrous. |
Leaves | (2–) 6–10(–16), flat to V-shaped, (2–) 10–30(–60) cm × 1–4 mm. |
1–4, 3–25 cm × 1–1.5 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. |
rays absent, often proliferous; bracts 2–4, longest erect, looking like continuation of culm, V-shaped, 3–6 cm × 1–3 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. |
1–3(–6), narrowly ellipsoid, weakly compressed, 5–10 × 2 mm; floral scales 8–16, laterally whitish or dull stramineous, medially green, weakly 3–4-ribbed, broadly ovate, 2.5 × 2 mm, apex acute to mucronate, mucro slightly excurved, 0.2–0.3 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. |
stamens 3; styles 0.8 mm; stigmas 1–1.3 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, abaxial angle more prominent than adaxial ones, 0.7 × 0.7 mm, apex emarginate, surfaces glabrous. |
Cyperus polystachyos |
Cyperus gracilis |
|
Phenology | Fruiting summer–early fall. | Fruiting summer–early fall. |
Habitat | Shores, ditches, swales between dunes | Disturbed, moist areas |
Elevation | 0–200 m (0–700 ft) | 0–100 m (0–300 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
|
CA; Australia [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.) |
Carex gracilis comprises diminutive plants with a delicate, arching habit and distinctive knoblike angles to the achenes. (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 > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. brizaeus, C. polystachyos var. leptostachyus, Pycreus polystachyos | |
Name authority | Rottbøll: Descr. Pl. Rar., 21. (1772) | R. Brown: Prodr., 213. (1810) |
Web links |