Cyperus cuspidatus |
Cyperus reflexus |
|
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coastal plain flatsedge |
bentawn flatsedge |
|
Habit | Herbs, annual, cespitose. | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. |
Culms | 1–6(–25), trigonous to roundly trigonous, (0.5–)2–5(–9) cm × 0.2–0.4–(0.6) mm, glabrous. |
roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
Leaves | 1–6, V-shaped, 1–6 cm × 0.3–1 mm. |
1–6, 10–40 cm, glabrous or essentially so. |
Inflorescences | heads digitate, loosely ovoid, 3–18 × 3–26 mm; rays (0–)1–6(–8), 2.5–20(–30) mm; bracts 2–3(–5), horizontal to ascending at 45(–60)°, V-shaped, 2–60 × 0.3–1.2 mm. |
heads ovoid to pyramidal, 9–15 mm diam.; rays 0 or 3–6, 0.5–4 cm, glabrous; bracts 3–4, longest erect, appearing as continuation of culm, others horizontal to ascending, 4–17 cm × 1.5–4 mm. |
Spikelets | (3–)10–20(–30), greenish to reddish brown, narrowly ellipsoid to oblong, 3–11 × (0.8–)1.2–1.5 mm; floral scales (3–)6–20(–28), laterally greenish to reddish brown, glossy, medially greenish to light reddish brown, strongly recurved, laterally ribless, medially strongly 3-ribbed, oblong-ovate, (0.8–)1–1.3 × 0.8–1(–1.2) mm, apex emarginate, cusp 0.6–1.2 mm. |
25–60, reddish with contrasting yellowish or greenish edges, oblong-lanceoloid, strongly compressed, 5–6(–15) × 1.5–2.5 mm; floral scales 10–22, laterally reddish, medially yellowish green, 2-keeled, laterally strongly 1-ribbed on each side, proximally grooved, ovate-elliptic, 1.4–2.2 × 0.8–1.5 mm, apex acute, apically scabridulous (sometimes glabrous). |
Flowers | stamens 2 or 3; anthers oblong-ovoid, 0.1(–0.2) mm; styles (0.2–)0.4–0.6 mm; stigmas 0.3–0.5 mm. |
stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
Achenes | brown, oblong-obovoid, (0.5–)0.6 × (0.3–)0.4 mm, base cuneate, apex blunt, surfaces coarsely papillose. |
reddish brown, stipitate, ovoid-ellipsoid, 0.8–0.9 × 0.3–0.4 mm, stipe 0.1–0.2 mm, apex acute to acuminate, surfaces reticulate or subtly rugulose. |
Cyperus cuspidatus |
Cyperus reflexus |
|
Phenology | Fruiting summer. | Fruiting late spring–fall (May–Oct). |
Habitat | Damp, disturbed soils | Muddy soils or shallow waters |
Elevation | 0–300 m (0–1000 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; FL; GA; SC; Mexico; Central America; South America
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FL; LA; OK; TX; Mexico; Central America (Costa Rica) |
Discussion | Cyperus reflexus is recognized by its reddish scales with contrasting greenish or yellow keels and by the laterally 1ribbed scales. The lateral rib is most often situated where the reddish and yellowish parts of the scale meet. Two varieties of C. reflexus, var. reflexus and var. fraternus, have been recognized (M. F. Denton 1978b). Both varieties were noted as intermingled in the North American and South American segments of the widely disjunct range of C. reflexus. Such variation does not seem significant at the varietal level (see G. C. Tucker 1994; G. C. Tucker and R. McVaugh 1993). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 158. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. arenicola, C. fraternus, C. pseudovegetus var. arenicola, C. reflexus var. fraternus | |
Name authority | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 204. (1816) | Vahl: Enum. Pl. 2: 299. (1805) |
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