Cyperus lanceolatus |
Cyperus reflexus |
|
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epiphytic flatsedge |
bentawn flatsedge |
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Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. |
Culms | trigonous, compressed, 15–75 cm × 0.5–3 mm, glabrous. |
roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
Leaves | 1–3, 5–30 cm × 1–2 mm. |
1–6, 10–40 cm, glabrous or essentially so. |
Inflorescences | spikes 1(–2), ovoid, 5–23 × 9–21 mm; rays 2–3(–4), 0–15 mm; if rays absent, head single, compact, sessile, (12–)15–20 mm diam.; bracts 2–3, horizontal to vertical, 2–14 cm × 0.5–3.5 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 | 1–6, oblong-lanceoloid, 5–26 × 2–3 mm; floral scales 12–54, closely imbricate, laterally yellowish brown, medially pale brown, occasionally greenish, laterally 1-ribbed, medially 3-ribbed, distinctly 2-keeled basally, ovate, 1.8–2.6 × 1.4–1.7 mm, apex obtuse. |
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; anthers 0.4–0.5 mm, connectives not prolonged; styles 0.3–1 mm; stigmas 0.6–0.8(–1) mm. |
stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
Achenes | brown, network of ridges forming isodiametric or square cells, stipitate, obovoid to ellipsoid, 1.1–1.3 × (0.5–)0.6 mm, apex acute to broadly rounded, surfaces minutely punctate or finely 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 lanceolatus |
Cyperus reflexus |
|
Phenology | Fruiting summer. | Fruiting late spring–fall (May–Oct). |
Habitat | Marshes | Muddy soils or shallow waters |
Elevation | 0–100 m (0–300 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; FL; GA; LA; TX; Mexico; Central America; South America; Africa
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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. 162. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. densus, C. humboldtianus, C. lanceolatus var. compositus, Pycreus densus | C. arenicola, C. fraternus, C. pseudovegetus var. arenicola, C. reflexus var. fraternus |
Name authority | Poiret: in J. Lamarck et al., Encycl. 7: 245. (1806) | Vahl: Enum. Pl. 2: 299. (1805) |
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