Cyperus reflexus |
Cyperus articulatus |
|
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bentawn flatsedge |
jointed flatsedge, priprioca |
|
Habit | Herbs, perennial, cespitose; rhizomes elongate, scaly, 2–3 mm wide. | Herbs perennial; rhizomes to 200 cm. |
Culms | roundly trigonous to terete, 30–80 cm × 1–1.6 mm, glabrous. |
to 25 cm apart, 1(–3) together, terete (scarcely compressed in drying), occasionally trigonous for apical 1/3, 40–140(–200) cm, 4–12 mm thick at base, (1.2–)1.5–2.5 mm thick at apex (with conspicuous transverse septa ca. 3 cm apart basally, to 3–5 mm apart apically), glabrous or infrequently scabrid on angles apically; sheaths at base of culm, 2–3, (5–)10–25 cm, loose, papery. |
Leaves | 1–6, 10–40 cm, glabrous or essentially so. |
usually bladeless, blades when present, cross ribs prominent, especially adaxially, (1–)10–20(–40) cm × 4–6(–9) 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 1(–5), broadly ovoid to ± umbellate, 15–45 × 10–30 mm; rays 5–7(–10), 0.3–8(–12) cm; 2d order rays occasionally present, 5–20 mm; bracts 2(–4), erect, longest appearing to be continuation of culm, deltate to lance-linear, 0.2–2(–9) cm × 1.5–4.5 mm; rachilla persistent, wings translucent, whitish, or stramineous, 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). |
(1–)5–10, linear, compressed, 10–35(–45) × 1.1–2 mm; floral scales deciduous, 15–45, spreading or appressed, laterally light brown, medially green to brown, laterally 1–2-ribbed, medially 3-ribbed, oblong-elliptic to ovate, 2.9–3.7 × 1.1–1.6(–1.8) mm, apex acute. |
Flowers | stamen 1; anthers 0.6–1 mm; styles 0.3–0.5 mm; stigmas 0.3–0.6 mm. |
anthers 1.7–2.4 mm; styles 1.2–3.6 mm; stigmas 1.7–6 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, obovoid-ellipsoid, 1.2–1.6 × 0.4–0.6 mm, stipe 0.1 mm, apex markedly apiculate, surfaces puncticulate. |
Cyperus reflexus |
Cyperus articulatus |
|
Phenology | Fruiting late spring–fall (May–Oct). | Fruiting summer. |
Habitat | Muddy soils or shallow waters | Marshes, shallow water, ditches |
Elevation | 0–200 m (0–700 ft) | 0–100 m (0–300 ft) |
Distribution |
FL; LA; OK; TX; Mexico; Central America (Costa Rica) |
AL; FL; GA; LA; MS; SC; TX; Mexico; Central America; South America; Asia; Africa
|
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.) |
In habit, Cyperus articulatus is reminscent of larger plants of Juncus or Schoenoplectus and is the only North American Cyperus with such a reedlike appearance. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 167. |
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 | C. articulatus var. multiflorus, C. articulatus var. nodosus, C. corymbosus var. subnodosus, C. nodosus, C. nodosus var. subnodosus, C. subnodosus |
Name authority | Vahl: Enum. Pl. 2: 299. (1805) | Linnaeus: Sp. Pl. 1: 44. (1753) |
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