Cyperus reflexus |
Cyperus serotinus |
|
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bentawn flatsedge |
tidalmarsh flatsedge |
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Habit | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. | Herbs, perennial, stoloniferous; stolons terminated by tubers. |
Culms | roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
trigonous, 50–100 cm × 5–8 mm, glabrous. |
Leaves | 1–6, 10–40 cm, glabrous or essentially so. |
3–6, V-shaped, 20–50 cm × 5–8(–10) 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. |
spikes not appearing lateral, rays 5–8, 2–7(–12) cm; bracts 3–4, ± horizontal to ascending at 45°, V-shaped, 5–25 cm × 1.5–8 mm; spikes 1–4, ovoid, 2–4 × 2–3 cm; rachis 1–2.7 cm, smooth or hispidulous; rachilla persistent, wingless or with hyaline wings scarcely 0.1 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). |
7–14, flattened, lanceoloid, 10–20 × 2–2.5 mm; floral scales 10–30, laterally dark brown to reddish brown, medially greenish, laterally 5–9-ribbed, ovate-deltate; anthers 3, 0.5 mm; styles 0.5 mm; stigmas 1.2–1.6 mm. |
Flowers | stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
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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, sessile, ellipsoid, 1.4–1.6 × 1.4–1.5 mm, apex obtuse, apiculate. |
Cyperus reflexus |
Cyperus serotinus |
|
Phenology | Fruiting late spring–fall (May–Oct). | Fruiting summer. |
Habitat | Muddy soils or shallow waters | Tidal marshes |
Elevation | 0–200 m (0–700 ft) | 0 m (0 ft) |
Distribution |
FL; LA; OK; TX; Mexico; Central America (Costa Rica) |
DE; NJ; PA; Eurasia [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.) |
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Source | FNA vol. 23. | FNA vol. 23, p. 164. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Juncellus |
Sibling taxa | ||
Synonyms | C. arenicola, C. fraternus, C. pseudovegetus var. arenicola, C. reflexus var. fraternus | Chlorocyperus serotinus, Juncellus serotinus |
Name authority | Vahl: Enum. Pl. 2: 299. (1805) | Rottbøll: Descr. Pl. Rar., 18. (1772) |
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