Cyperus oxylepis |
Cyperus grayoides |
|
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sharpscale flatsedge |
Illinois flatsedge, Mohlenbrock's sedge, umbrella sedge |
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Habit | Herbs, perennial, cespitose, coarse, (culms, leaves, bracts, and rays viscid). | Herbs, perennial, cespitose, rhizomatous, tuberlike. |
Culms | roundly trigonous, 10–50 cm × 0.9–2.4 mm. |
trigonous, 5–35 cm × 0.7–1.2 mm, glabrous. |
Leaves | adaxial face concave, becoming flat to trigonous apically, 10–46 cm × 1.5–4 mm, margins involute. |
V-shaped, 5–25 cm × 1.5–3.5 mm, slightly scabridulous on abaxial margins, midrib. |
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 loosely ± globose, 15–25 mm wide; rays 1–10 cm; rachis 1–4 mm; bracts 3–7, ascending, V-shaped, 3–20 cm × 1–3 mm; rachilla deciduous, wingless. |
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. |
3–24, compressed, oblong-lanceoloid, 4–12 × 2.5–3.2 mm; floral scales deciduous, 3–9, pale reddish brown, ovate, laterally 3–5-ribbed, 2.5–3 × 2–2.4 mm, apex acute to obtuse. |
Flowers | anthers 0.6–0.8 mm; styles 0.8–1.6 mm; stigmas 1–1.4 mm. |
anthers 1–1.2 mm; styles 0.4–0.6 mm; stigmas 1–2 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, ± stipitate, ellipsoid, 2–2.4 × 0.9–1.2 mm, apex obtuse, apiculate, surfaces glabrous, puncticulate, or papillose. |
2n | = 166. |
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Cyperus oxylepis |
Cyperus grayoides |
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Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Ditches and disturbed places in marshes, often in saline soil | Sand prairies, waste places, fallow fields |
Elevation | 0–100 m (0–300 ft) | 100–300 m (300–1000 ft) |
Distribution |
AR; FL; GA; LA; MS; SC; TX; Mexico; South America [Introduced in North America]
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AR; IL; LA; MO; TX
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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.) |
Of conservation concern. Cyperus grayoides is in the Center for Plant Conservation’s National Collection of Endangered Plant’s. See frontispiece. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 171. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Name authority | Nees ex Steudel: Syn. Pl. Glumac. 2: 25. (1855) | Mohlenbrock: Brittonia 11: 255, fig. 1. (1959) |
Web links |