Cyperus seslerioides |
Cyperus distinctus |
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Texas flatsedge |
swamp 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. |
terete, 40–60(–90)cm, glabrous. |
Leaves | 1–5, flat, involute toward apex, 3–18 cm × 1–2.5(–3) mm. |
flat, 35–70 cm × 4–9(–12) 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. |
heads hemispheric, 10–20 mm diam.; rays 5–9(–14), 3.5–10 cm; 2d order rays 0.5–2 cm; bracts 5–10, ± horizontal, flat, 12–40(–50) cm × 2–7 mm. |
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. |
(25–)35–50(–60), ovoid, compressed, (3.5–)5–12(–14) × 2.5–3.5(–4) mm; floral scales 10–32, golden brown to brown, 2-keeled, laterally ribless, narrowly lanceolate, 2–2.2(–3) × 0.8–1.4 mm. |
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. |
stamen 1; anthers 1 mm; styles 1 mm; stigmas 0.5 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, stipitate, narrowly ellipsoid, 1.5–2 × 0.2–0.4 mm, base swollen, spongy, stipe 0.2 × 0.2–0.3 mm, apex acute, beak slender, 0.2 mm, surfaces puncticulate. |
Cyperus seslerioides |
Cyperus distinctus |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Seeps, damp meadows in montane forests | Damp grasslands, roadsides, ditches |
Elevation | 1000–2000 m (3300–6600 ft) | 0–50 m (0–200 ft) |
Distribution |
AZ; TX; Mexico; South America; Central America (Honduras) |
FL; GA; LA; SC; West Indies (Bahamas) |
Discussion | The slender achenes with conspicuously swollen bases distinguish Cyperus distinctus from other species of subg. Pycnostachys. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 157. | FNA vol. 23, p. 154. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. virens var. brittonii | |
Name authority | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 209. (1816) | Steudel: Syn. Pl. Glumac. 2: 24. (1855) |
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