Cyperus prolixus |
Cyperus alopecuroides |
|
---|---|---|
mosquito flatsedge |
foxtail flatsedge |
|
Habit | Herbs, perennial; rhizomes 3–20 cm × 1–2 cm, indurate. | Herbs, perennial, rhizomatous, coarse. |
Culms | stoutly trigonous, thickened, 50–300 cm × 5–30 mm, basally indurate, glabrous. |
trigonous, 150–250 cm × 2–15 mm, glabrous. |
Leaves | V-shaped, with cross ribs, 40–130 cm × 10–15 mm, margins and keel scabrid. |
inversely W-shaped, 30–150 cm × 6–22 mm. |
Inflorescences | spikes appressed-ascending, narrowly cylindric, (2–)3–45 mm × (4–)7–10 mm; rays (5–)9–12, 2–22(–30) cm; 2d order rays distinctly flattened, 1–10 cm; 3d order rays flattened, 0.5–3 cm; rachis 2.5–4 cm; bracts (6–)9–10, ascending at 45–75°, V- or inversely W-shaped, (5–)15–90 cm × 0.5–20 mm; rachilla persistent, wings 0.2–0.4 mm wide. |
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 | (4–)10–35, appressed-ascending, compressed, linear, 7–12(–15) × 0.6–1.2 mm; floral scales deciduous, 6–20, marginally clear, laterally brown, medially green, laterally 2–3-ribbed, medially 1-ribbed, oblong-ovate, (3.2–) 3.8–4.3 × 1.2–1.7 mm, apex spreading, acute to obtuse, mucronulate. |
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 0.7–0.9 mm, connective apex bright red, oblong, to 0.1 mm; styles 0.8–1.3 mm; stigmas 2–3.3 mm. |
anthers 2, 0.4–0.5 mm; styles 0.8–1 mm; stigmas 2, 0.4 mm. |
Achenes | brown, sessile, narrowly ellipsoid, 1.8–2.5 × 0.8–1.3 mm, apex ± acute, not apiculate, surfaces puncticulate. |
dark brown, sessile, ellipsoid to obovoid, 0.9 × 0.4–0.5 mm, surfaces finely puncticulate. |
Cyperus prolixus |
Cyperus alopecuroides |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Coastal marshes | Pond shores, stream banks |
Elevation | 0–10 m [0–30 ft] | 0–30 m [0–100 ft] |
Distribution |
LA; Mexico; Central America; South America |
FL; West Indies; Asia; Africa; Australia [Introduced in North America] |
Discussion | Cyperus prolixus produces large plants, similar in habit to C. giganteus and C. papyrus but easily distinguished by flattened rays. (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. 167. | FNA vol. 23, p. 173. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. amplissimus | |
Name authority | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 206. (1816) | Rottbøll: Descr. Pl. Rar., 20. (1772) |
Web links |