Cyperus filiculmis |
Cyperus seslerioides |
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Texas flatsedge |
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Habit | Herbs, perennial, cespitose, bases cormose; rhizomes knotted, beaded. | Herbs, perennial, cespitose; rhizomes knotty, much branched, 2–5 mm diam., scaly. |
Culms | trigonous, 15–48 cm × 0.4–1 mm, glabrous. |
roundly trigonous, basally with dark fibrous remnants of old leaf sheaths, (0.5–)4–30 cm × 0.4 –1.1 mm, glabrous. |
Leaves | flat, 10–30 cm × 0.5–2 mm. |
1–5, flat, involute toward apex, 3–18 cm × 1–2.5(–3) mm. |
Inflorescences | spikes rather densely ovoid, 1–3.5 cm; rays 0 (sometimes 1–4), 1–6 cm; rachis 1–4 mm; bracts 3–4, horizontal to slightly reflexed, flat, 6–25 cm; rachilla ± deciduous, wingless. |
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. |
Spikelets | 25–60, compressed, oblong-lanceoloid, 5–12 × 2.2–3.5 mm; floral scales deciduous, 5–15, yellowish to yellowish brown, laterally 4–5-ribbed, oblong-ovate, 2.6–3.6 × 1.4–2 mm, margins loosely spreading or clasping achene. |
(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. |
Flowers | anthers 0.8–1 mm; styles 1 mm; stigmas 1.5–2.5 mm. |
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. |
Achenes | dark grayish brown, sessile, narrowly oblong, 1.8–2.2 × 0.5–0.8 mm, apex obtuse, apiculate, surfaces puncticulate. |
brown to blackish, trigonous, broadly obovoid, 0.5–1 × 0.3–0.75 mm, base slightly stipelike, ± cuneate to rounded, apex apiculate, papillose. |
Cyperus filiculmis |
Cyperus seslerioides |
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Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Well-drained, open roadsides, fields, pine barrens, dunes | Seeps, damp meadows in montane forests |
Elevation | 0–200 m (0–700 ft) | 1000–2000 m (3300–6600 ft) |
Distribution |
AL; FL; GA; LA; MD; MS; NC; SC; TX; VA |
AZ; TX; Mexico; South America; Central America (Honduras) |
Discussion | Cyperus filiculmis has long been treated within a broader and more widely used concept of C. filiculmis (C. lupulinus); see B. G. Marcks (1974) (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 175. | FNA vol. 23, p. 157. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. martindalei | |
Name authority | Vahl: Enum. Pl. 2: 328. (1805) | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 209. (1816) |
Web links |