Cyperus reflexus |
Cyperus papyrus |
|
---|---|---|
bentawn flatsedge |
Egyptian paper-reed, papyrus |
|
Habit | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. | Herbs, perennial, rhizomatous, stout. |
Culms | roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
roundly trigonous, 300–500 cm × 15–45 mm, glabrous. |
Leaves | 1–6, 10–40 cm, glabrous or essentially so. |
bladeless. |
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 loosely cylindric, 10–20 × 6–10 mm; rays 40–100, drooping or arching, slender, 10–30 cm; 2d order rays 8–20 cm; bracts 4–10, ± erect, V-shaped, 3–8 cm × 4–15 mm; 2d order bracts 2–5, (1.5–)4–16 cm × 0.5–2 mm; rachilla persistent, separating laterally, remaining firmly attached basally, wings 0.3–0.4 mm wide. |
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). |
6–30, slightly compressed, linear, ± quadrangular, 6–10 × 0.8–1 mm; floral scales 6–16, reddish beside 5-ribbed green medial part, white to hyaline near margins, ovate-elliptic, 1.8–2.2 × 1.2–1.5 mm, apex acute to obtuse. |
Flowers | stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
anthers 0.8–1 mm (connectives prolonged beyond anther as red subulate appendage 0.2–0.5 mm, apex usually setose); styles 0.2–0.4 mm; stigmas 0.8–1.2 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. |
pale brown, sessile, oblong, 0.8–1 × 0.4 mm, apex scarcely apiculate, surfaces puncticulate. |
Cyperus reflexus |
Cyperus papyrus |
|
Phenology | Fruiting late spring–fall (May–Oct). | Fruiting summer. |
Habitat | Muddy soils or shallow waters | Stream banks, marshes |
Elevation | 0–200 m (0–700 ft) | 0–30 m (0–100 ft) |
Distribution |
FL; LA; OK; TX; Mexico; Central America (Costa Rica) |
FL; s Europe; sw Asia; Africa [Introduced in North America] |
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.) |
Cyperus papyrus is conspicuous in the field by its great height, leafless culm, and open, hemispheric inflorescence with drooping rays. Ancient Egyptians, Greeks, and Romans prepared paper from the pith of the culms of Cyperus papyrus, which is abundant along the Nile River. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 173. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. arenicola, C. fraternus, C. pseudovegetus var. arenicola, C. reflexus var. fraternus | |
Name authority | Vahl: Enum. Pl. 2: 299. (1805) | Linnaeus: Sp. Pl. 1: 47. (1753) |
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