Cyperus reflexus |
Cyperus distinctus |
|
---|---|---|
bentawn flatsedge |
swamp flatsedge |
|
Habit | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. | Herbs, perennial, cespitose, rhizomatous. |
Culms | roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
terete, 40–60(–90)cm, glabrous. |
Leaves | 1–6, 10–40 cm, glabrous or essentially so. |
flat, 35–70 cm × 4–9(–12) mm. |
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. |
heads hemispheric, 10–20 mm diam.; rays 5–9(–14), 3.5–10 cm; 2d order rays 0.5–2 cm; bracts 5–10, ± horizontal, flat, 12–40(–50) cm × 2–7 mm. |
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). |
(25–)35–50(–60), ovoid, compressed, (3.5–)5–12(–14) × 2.5–3.5(–4) mm; floral scales 10–32, golden brown to brown, 2-keeled, laterally ribless, narrowly lanceolate, 2–2.2(–3) × 0.8–1.4 mm. |
Flowers | stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
stamen 1; anthers 1 mm; styles 1 mm; stigmas 0.5 mm. |
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. |
brown, stipitate, narrowly ellipsoid, 1.5–2 × 0.2–0.4 mm, base swollen, spongy, stipe 0.2 × 0.2–0.3 mm, apex acute, beak slender, 0.2 mm, surfaces puncticulate. |
Cyperus reflexus |
Cyperus distinctus |
|
Phenology | Fruiting late spring–fall (May–Oct). | Fruiting summer. |
Habitat | Muddy soils or shallow waters | Damp grasslands, roadsides, ditches |
Elevation | 0–200 m (0–700 ft) | 0–50 m (0–200 ft) |
Distribution |
FL; LA; OK; TX; Mexico; Central America (Costa Rica) |
FL; GA; LA; SC; West Indies (Bahamas) |
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.) |
The slender achenes with conspicuously swollen bases distinguish Cyperus distinctus from other species of subg. Pycnostachys. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 154. |
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 | C. virens var. brittonii |
Name authority | Vahl: Enum. Pl. 2: 299. (1805) | Steudel: Syn. Pl. Glumac. 2: 24. (1855) |
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