Cyperus seslerioides |
Cyperus lentiginosus |
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Texas flatsedge |
Latin American flatsedge |
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Habit | Herbs, perennial, cespitose; rhizomes knotty, much branched, 2–5 mm diam., scaly. | Herbs, perennial, cespitose, rhizomatous. |
Culms | roundly trigonous, basally with dark fibrous remnants of old leaf sheaths, (0.5–)4–30 cm × 0.4 –1.1 mm, glabrous. |
trigonous, (1–) 20–40(–75) cm × 1–1.5(–2.5) mm, glabrous. |
Leaves | 1–5, flat, involute toward apex, 3–18 cm × 1–2.5(–3) mm. |
inversely W-shaped, 10–40(–70) cm × (1–)3–6(–10) mm. |
Inflorescences | heads hemispheric to spheric, (3–)6–15(–24) mm diam.; rays absent; bracts 2–5, horizontal to reflexed, parallel to culm, 1–13 cm × 1–3 mm, margins and keel sparsely minutely scabridulous distally. |
spikes 1(–3), broadly and loosely ovoid to oblong-ellipsoid, (15–)20–30(–50) × 20–30(–45) mm; bracts (3–)5–7(–10), ascending at 30(–45)°, inversely W-shaped, 10–30(–50) cm × (1–)3–5(–11) mm; rays (2–)3–6(–12), (1–)3–10(–17) cm; rachilla deciduous, wings ca. 0.3 mm wide. |
Spikelets | (5–)20–60(–100), whitish to greenish or brownish, ovoid to oblong-lanceoloid, compressed, 3–7 × 2–4 mm; floral scales (8–)10–12(–24), laterally milky white (infrequently yellowish, pale greenish, brown, or bronze-white), medially green or white, laterally ribless, medially 3-ribbed, ovate to ovate-lanceolate, 1.6–3(–3.4) × 0.8–1.3 mm, apex mucronate to acuminate. |
(10–)25–50(–100), ± terete, (appearing compressed due to excurved apices of floral scales), (8–)12–15(–24) × (0.8–)1.1–1.4(–1.8) mm; floral scales persistent, (4–)6–8(–14), golden brown, off-white to stramineous, densely red-glandular punctate, green medially, 3–4-ribbed laterally, 3–5-ribbed medially, oblong-lanceolate, (3.2–)4–4.5 × 1.2–1.6 mm, apex blunt, mucronulate to mucronate, mucro 0.2–0.5 mm; proximal scales mucronulate, distal scales mucronate; terminal scale conduplicate. |
Flowers | stamens 3; anthers linear, (0.4–)0.6–0.8(–1.1) mm, connective not prolonged; styles 0.8–1.8 mm; stigmas (0.5–)1–1.5(–2) mm. |
anthers 0.5–0.8(–1.4) mm; styles 0.8–1 mm; stigmas 1–2 mm. |
Achenes | brown to blackish, trigonous, broadly obovoid, 0.5–1 × 0.3–0.75 mm, base slightly stipelike, ± cuneate to rounded, apex apiculate, papillose. |
brown, ± sessile to stipitate, oblong-ellipsoid, 1.7–2 × 0.6–0.7 mm, 0.1(–0.2) × 0.2 mm, apex rounded, apiculate from dark purple style base, surfaces papillose. |
Cyperus seslerioides |
Cyperus lentiginosus |
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Phenology | Fruiting summer. | Fruiting spring–summer. |
Habitat | Seeps, damp meadows in montane forests | Thickets, open woods |
Elevation | 1000–2000 m (3300–6600 ft) | 0–50 m (0–200 ft) |
Distribution |
AZ; TX; Mexico; South America; Central America (Honduras) |
FL; TX; Mexico; West Indies |
Discussion | Cyperus lentiginosus has been treated as a variety of C. tenuis (G. Kükenthal 1935–1936). The two taxa differ in the longer scales with cuspidate apices of C. lentiginosus, the inversely W-shaped leaves and bracts (those of C. tenuis are V-shaped), and the open spikes (those of C. tenuis are dense). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 157. | FNA vol. 23. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. strigosus var. gracilis, C. tenuis var. lentiginosus | |
Name authority | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 209. (1816) | Millspaugh & Chase: Publ. Field Columbian Mus., Bot. Ser. 3: 74. (1903) |
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