Cyperus thyrsiflorus |
Cyperus oxylepis |
|
---|---|---|
southern flatsedge |
sharpscale flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, cespitose, coarse, (culms, leaves, bracts, and rays viscid). |
Culms | trigonous, (15–) 20–40(–65) cm × 0.5–1 mm, glabrous. |
roundly trigonous, 10–50 cm × 0.9–2.4 mm. |
Leaves | V-shaped, (10–)20–40 cm × 0.8–2.8(–3) mm, glabrous. |
adaxial face concave, becoming flat to trigonous apically, 10–46 cm × 1.5–4 mm, margins involute. |
Inflorescences | spike 1, densely oblong-cylindric, (15–)25–35(–40) × 12–18(–22) mm, (spikelets loosely spaced, 7–9 per 5 mm of rachis); rays (5–)6–8(–11), 0.5–4(–7.5) cm; bracts (4–)5–7(–8), ascending at 30º, (4–)10–30(–35) cm × (1–)2–4(–7) mm; rachilla deciduous, wings persistent, 0.4–0.5 mm wide. |
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. |
Spikelets | (20–)40–80(–100), linear, ± cylindric, scarcely compressed, (4.5–)6–9(–11) × (0.5–) 0.6–0.7(–1) mm; floral scales persistent, (1–)2–3(–4), appressed, medially green, laterally light brown to tawny or bronze, medially (1–)3-ribbed, laterally 3-ribbed, oblong, (2.6–)2.8–3.2(–3.4) × (1–)1.2(–1.4) mm, apex acute, mucronulate, mucro to 0.1(–0.2) mm. |
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. |
Flowers | anthers 0.6–0.8 mm; styles (0.4–)0.6–1(–1.2) mm; stigmas persistent on achenes, prominently exserted from floral scales, (1.5–)2–3(–4) mm. |
anthers 0.6–0.8 mm; styles 0.8–1.6 mm; stigmas 1–1.4 mm. |
Achenes | brown to reddish brown, stipitate, narrowly oblong, 1.8–2.1 × (0.4–)0.5(–0.7) mm, stipe 0.1–0.2 × 0.1–0.2 mm, apex apiculate, acute, surfaces puncticulate. |
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. |
Cyperus thyrsiflorus |
Cyperus oxylepis |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Dry, open woods | Ditches and disturbed places in marshes, often in saline soil |
Elevation | 0–200 m (0–700 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; FL; GA; LA; TX; Mexico; South America; West Indies |
AR; FL; GA; LA; MS; SC; TX; Mexico; South America [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.) |
|
Source | FNA vol. 23, p. 185. | FNA vol. 23, p. 171. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. anceps, C. dissitiflorus, C. pallens, C. regiomontanus var. pallens, C. tribrachiatus, Mariscus dissitiflorus, Mariscus pallens, Mariscus tribrachiatus | |
Name authority | Junghuhn: Linnaea 6: 24. (1831) | Nees ex Steudel: Syn. Pl. Glumac. 2: 25. (1855) |
Web links |