Cyperus oxylepis |
Cyperus alopecuroides |
|
---|---|---|
sharpscale flatsedge |
foxtail flatsedge |
|
Habit | Herbs, perennial, cespitose, coarse, (culms, leaves, bracts, and rays viscid). | Herbs, perennial, rhizomatous, coarse. |
Culms | roundly trigonous, 10–50 cm × 0.9–2.4 mm. |
trigonous, 150–250 cm × 2–15 mm, glabrous. |
Leaves | adaxial face concave, becoming flat to trigonous apically, 10–46 cm × 1.5–4 mm, margins involute. |
inversely W-shaped, 30–150 cm × 6–22 mm. |
Inflorescences | spikes ovoid, 1–5.5 cm wide; rays usually 3–6, 0.5–5 cm, glabrous; sometimes absent in small plants; if absent, inflorescence a congested head of spikelets 1–3.5 cm diam.; 2d order rays 0–3, 1–3 cm; bracts 3–5, vertical to ascending at 45°, 2.5–25 cm × 1.2–4 mm, margins involute; 2d order bracts 0–2, 5–20 mm; rachilla persistent, wingless. |
spikes 1–4, cylindric, 1.5–4 cm × 7–15 mm; rays 3–9, 10–26 cm; 2d order rays 2–11 cm; 3d order rays 1–4 cm (or absent); bracts 3–5, ± horizontal, 20–100 cm × 3–15 mm; 2d order bracts 2–7 cm × 2–7 mm; 3d order bracts 2–5 cm × 2–4 mm (or absent); rachilla persistent, wingless or wing hyaline, narrow, 0.1 mm wide. |
Spikelets | 5–24, greenish yellow to golden brown, oblong to linear-lanceoloid, quadrangular, strongly compressed, 7–20(–30) × 2.5–4(–6) mm; floral scales 10–20(–40), spreading, pale green to stramineous, laterally 2–3-ribbed, ovate-lanceolate, 3.1–4 × 1.5–2.4 mm, apex with mucro 0.2–0.8 mm. |
50–100, linear, ± quadrangular, slightly compressed, 8–11 × 0.9–1.2 mm; floral scales 15–30, marginally clear, laterally reddish along midrib, medially green, laterally 3–4 ribbed, medially 3–5-ribbed, ovate, 1–2–1.6 × 1.1–1.3 mm, apex mucronulate. |
Flowers | anthers 0.6–0.8 mm; styles 0.8–1.6 mm; stigmas 1–1.4 mm. |
anthers 2, 0.4–0.5 mm; styles 0.8–1 mm; stigmas 2, 0.4 mm. |
Achenes | light to dark brown, rarely somewhat reddish, stipitate, ellipsoid, 2–2.4 × 0.5–0.8 mm, base cuneate, stipe whitish, spongy, 0.2–0.3 × 0.2–0.4 mm, apex acute, persistent style forming beak 0.5–1.2 mm, surfaces glabrous or finely papillose. |
dark brown, sessile, ellipsoid to obovoid, 0.9 × 0.4–0.5 mm, surfaces finely puncticulate. |
Cyperus oxylepis |
Cyperus alopecuroides |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Ditches and disturbed places in marshes, often in saline soil | Pond shores, stream banks |
Elevation | 0–100 m (0–300 ft) | 0–30 m (0–100 ft) |
Distribution |
AR; FL; GA; LA; MS; SC; TX; Mexico; South America [Introduced in North America]
|
FL; West Indies; Asia; Africa; Australia [Introduced in North America] |
Discussion | Cyperus oxylepis is easily recognized by its sticky leaves, culms, and bracts (in living plants), involute leaves,and golden brown spikelets. The ovate-lanceolate floral scales and the ellipsoid, brownish achene with a persistent beak distinguish C. oxylepis from other species with deciduous floral scales. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus alopecuroides has been introduced in Polk County, Florida. Plants of Cyperus alopecuroides might be confused with C. digitatus; large size and the biconvex achenes with two stigmas characterize C. alopecuroides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 171. | FNA vol. 23, p. 173. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Name authority | Nees ex Steudel: Syn. Pl. Glumac. 2: 25. (1855) | Rottbøll: Descr. Pl. Rar., 20. (1772) |
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