Cyperus difformis |
Cyperus filiformis |
|
---|---|---|
Asian flatsedge, smallflower umbrella sedge, variable flatsedge |
wiry flatsedge |
|
Habit | Herbs, annual, cespitose. | Herbs, perennial. |
Culms | 1–15, trigonous, 7–30 cm × 1.2–2.5 mm, soft (flattened in pressing), glabrous. |
trigonous, 20–36 cm × 0.5–1 mm. |
Leaves | 2–7, flat, (2–)7–22 cm × 2.2–4 mm. |
flat, 4–22 cm × 1–2 mm. |
Inflorescence(s) | 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. |
a single loose cluster of spikelets; rays 0–(1–2), if present, to 4 cm; bracts 2–3, ascending, 1–8 cm × 0.7–1 mm; rachilla with wings 0.6 mm wide. |
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. |
2–8, linear, terete, 6–20 × 0.7–1 mm; floral scales 6–10, medially green, laterally brown, medially faintly 3-ribbed, laterally faintly 3–5-ribbed, ovate, 2.5–3 × 2 mm. |
Flowers | stamens 1 or 2; anthers ovoid-ellipsoid, 0.1 mm, connective not prolonged; styles 0.1 mm; stigmas 0.1–0.3 mm. |
anthers 1 mm; styles 0.5 mm; stigmas 1 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. |
black, sessile, obovoid, 2 × 0.8 mm, apex scarcely apiculate, surfaces puncticulate. |
Cyperus difformis |
Cyperus filiformis |
|
Phenology | Fruiting summer. | Fruiting spring–fall. |
Habitat | Disturbed, muddy soils, shallow waters | Damp, disturbed places |
Elevation | 0–1000 m (0–3300 ft) | 0–20 m (0–100 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]
|
FL; West Indies |
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.) |
|
Source | FNA vol. 23, p. 156. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Diclidium |
Sibling taxa | ||
Synonyms | C. lateriflorus | C. floridanus, Mariscus filiforme, Mariscus floridensis, Torulinium filiforme |
Name authority | Linnaeus: Cent. Pl. II, 6. (1756) | Swartz: Prodr., 20. (1788) |
Web links |