Cyperus retrorsus |
Cyperus reflexus |
|
---|---|---|
pine barren flatsedge |
bentawn flatsedge |
|
Habit | Herbs, perennial, cespitose, shortly rhizomatous. | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. |
Culms | trigonous, 20–50(–85) cm × 1–2(–4) mm, glabrous. |
roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
Leaves | 3–6(–10), 10–40(–55) cm × 1.5–4(–5) mm, V- to inversely W-shaped. |
1–6, 10–40 cm, glabrous or essentially so. |
Inflorescence(s) | spike 1, densely oblong-ovoid often with small basal branches, 8–16 × 4–12(–16) mm; rays 4–8(–11), 0.5–3.5(–8.5) cm; bracts (3–)4–6(–10), ascending at (30–)45°, flat to broadly V-shaped, (4–)14–30(–55) cm × 1–5 mm, scabridulous along margins only; rachilla deciduous, wings persistent, 0.2–0.3 mm wide. |
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 | 40–120, oblong-lanceoloid, subterete, 2.2–4(–4.5) × 0.8–1.6 mm; distal spikelet spreading or ascending; floral scales persistent, 2–5, appressed, brown to stramineous, or fuscous and lustrous, medially greenish and 1(–3)-ribbed, laterally greenish to yellowish white and 3–4-ribbed, oblong to oblong-lanceolate, 1.8–2.5 × 1–1.5 mm, subcoriacous. |
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 | anthers 0.3–0.5 mm; styles 0.5–0.8 mm; stigmas 0.6–0.9 mm. |
stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
Achenes | brown, oblong-ellipsoid, 1.2–1.7 × 0.5–0.6 mm, base cuneate, apex subacute, surfaces 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 retrorsus |
Cyperus reflexus |
|
Phenology | Fruiting summer (Jun–Aug). | Fruiting late spring–fall (May–Oct). |
Habitat | Open woods and thickets in moist to dry, sandy soils | Muddy soils or shallow waters |
Elevation | 0–1000 m (0–3300 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; AR; DC; DE; FL; GA; LA; MD; MO; MS; NC; NJ; NY; OK; SC; TN; TX; VA; Mexico (Tamaulipas)
|
FL; LA; OK; TX; Mexico; Central America (Costa Rica) |
Discussion | Cyperus retrorsus was reported in Indiana (M. L. Horvat 1941); we have been unable to confirm the report. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. 187. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | Mariscus cylindricus, C. cylindricus, Mariscus retrorsus | C. arenicola, C. fraternus, C. pseudovegetus var. arenicola, C. reflexus var. fraternus |
Name authority | Chapman: Bot. Gaz. 3: 17. (1878) | Vahl: Enum. Pl. 2: 299. (1805) |
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