Cyperus reflexus |
Cyperus subg. Pycnostachys |
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bentawn flatsedge |
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Habit | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. | |
Culms | roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
and leaves with non-Kranz anatomy (C3). |
Leaves | 1–6, 10–40 cm, glabrous or essentially so. |
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Inflorescences | 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. |
spikes; rachilla persistent, wingless. |
Spikelets | 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). |
borne in digitate clusters (rarely singly) or in umbellate or glomerulate heads; floral scales deciduous, 2-keeled or folded (conduplicate). |
Flowers | stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
stamens 1–3; stigmas 3. |
Achenes | 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. |
trigonous, plano-convex, or terete. |
Cyperus reflexus |
Cyperus subg. Pycnostachys |
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Phenology | Fruiting late spring–fall (May–Oct). | |
Habitat | Muddy soils or shallow waters | |
Elevation | 0–200 m (0–700 ft) | |
Distribution |
FL; LA; OK; TX; Mexico; Central America (Costa Rica) |
Worldwide |
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.) |
Species ca. 150 (22 in the flora). The greatest species diversity of Cyperus subg. Pycnostachys is found in the lowland forests of Central America, South America, Africa, and Malesia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | C. arenicola, C. fraternus, C. pseudovegetus var. arenicola, C. reflexus var. fraternus | C. subg. Protocyperus |
Name authority | Vahl: Enum. Pl. 2: 299. (1805) | C. B. Clarke: in J. D. Hooker, Fl. Brit. India 6: 597. (1893) |
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