Cyperus difformis |
Cyperus prolifer |
|
---|---|---|
Asian flatsedge, smallflower umbrella sedge, variable flatsedge |
miniature flatsedge |
|
Habit | Herbs, annual, cespitose. | Herbs, perennial, cespitose, rhizomatous. |
Culms | 1–15, trigonous, 7–30 cm × 1.2–2.5 mm, soft (flattened in pressing), glabrous. |
trigonous to terete, 20–100 cm × 2–6 mm, soft (flattened in drying), glabrous, often flopping over and rooting at base of rays. |
Leaves | 2–7, flat, (2–)7–22 cm × 2.2–4 mm. |
blades reduced to sheath. |
Inflorescences | heads dense, 7–17 mm diam.; when rays short, heads sessile or nearly so, then densely irregularly lobate, 12–35 mm diam.; rays 1–5, 2–32 mm; bracts 2–4, longest bract erect or nearly so, appearing as continuation of culm, other bracts horizontal to ascending, 1–22 cm × 0.5–3.5 mm, margins and keel minutely scabridulous. |
rays 100–250, 5–16 cm; 2d order rays 0.5–5 cm; bracts 2–3, horizontal or reflexed, 4–12 cm × 1.5–4 mm. |
Spikelets | 30–120, greenish brown to purplish brown, oblong-ellipsoid, compressed, (2–)3–5(–6) × 0.8–1.2 mm; floral scales (6–)12–20(–30), laterally clear margins, stramineous to deep purple, medially greenish, stramineous, or purplish, laterally ribless, medially 3-ribbed, obovate to orbiculate, 0.6–0.8 × 0.6–0.8 mm, apex mucronulate. |
1–30, linear-lanceoloid, ellipsoid to narrowly ovoid, compressed-quadrangular, 6–17 × 1–1.5 mm; floral scales 5–12, reddish brown, 1–3-ribbed, 1.2–1.7 × 0.7–0.9 mm, apex mucronulate. |
Flowers | stamens 1 or 2; anthers ovoid-ellipsoid, 0.1 mm, connective not prolonged; styles 0.1 mm; stigmas 0.1–0.3 mm. |
stamens 3; anthers 1–1.2 mm; styles 0.3 mm; stigmas 1–1.3 mm. |
Achenes | light brown, obovoid-ellipsoid, 0.6–0.8 × 0.3–0.4 mm (as long as subtending scale), base cuneate, apex obtuse, apiculate, surfaces finely reticulate, papillose. |
brown, obovoid, 0.4 × 0.2 mm, base stipelike to nearly cuneate, apex obtuse, surfaces finely reticulate. |
Cyperus difformis |
Cyperus prolifer |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Disturbed, muddy soils, shallow waters | Pond shores, marshes |
Elevation | 0–1000 m (0–3300 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; AZ; CA; FL; GA; ID; KY; LA; MS; NC; NJ; NM; OR; PA; SC; TN; TX; VA; Mexico; South America; West Indies (Puerto Rico); Central America (Nicaragua, Panama); Eurasia; Indian Ocean Islands; Pacific Islands; Australia [Introduced in North America]
|
CA; FL; tropical e Africa [Introduced in North America] |
Discussion | Cyperus difformis is naturalized in the New World and native to the Old World, where it ranges from southern Europe to southern Africa and eastward to Southeast Asia and Australia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus prolifer has long been cultivated in fish ponds and water gardens and has been reported under the name C. isocladus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 156. | FNA vol. 23, p. 152. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. lateriflorus | C. isocladus |
Name authority | Linnaeus: Cent. Pl. II, 6. (1756) | Lamarck: in J. Lamarck and J. Poiret, Tabl. Encycl. 1: 147. (1791) |
Web links |