Cyperus difformis |
Cyperus spectabilis |
|
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Asian flatsedge, smallflower umbrella sedge, variable flatsedge |
showy sedge, spectacular flatsedge |
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Habit | Herbs, annual, cespitose. | Herbs, perennial, rhizomatous. |
Culms | 1–15, trigonous, 7–30 cm × 1.2–2.5 mm, soft (flattened in pressing), glabrous. |
trigonous, (12–)30–80(–90) cm × 0.7–1.7 mm, glabrous or nearly so. |
Leaves | 2–7, flat, (2–)7–22 cm × 2.2–4 mm. |
flat to V-shaped, 20–45 cm × 2–4 mm, margins and keel minutely scabridulous. |
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. |
spike 1, loosely ovoid to ovoid-ellipsoid, (1.5–)2.5–7 × (1–)1.5–3.5 cm; rays 1–4, 1–15 cm; rachis 1–2 cm; bracts 2–4, oblique or ascending, 1–15(–24) cm × 0.4–3.5 mm, keel, margins scabrid; rachilla ± deciduous, wingless. |
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. |
(3–)8–40, linear, compressed-quadrangular, 8–18 × (2.4–)2.8–4 mm; floral scales deciduous, (2–)4–12, laterally light brown to reddish brown, medially green or light brown, laterally 2–3-ribbed, oblong-ovate, 1.6–2.6 × (1.5–)1.6–2.2(–2.4) mm, apex obtuse, sometimes mucronulate, medially glabrous. |
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 0.4–0.6 mm; styles 0.3–0.6 mm; stigmas 0.6–1 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. |
brownish, stipitate, ellipsoid, 1.6–2 × (0.7–)0.9–1 mm, stipe whitish, 0.1–0.2 mm, apex obtuse, slightly apiculate, surfaces papillose. |
Cyperus difformis |
Cyperus spectabilis |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Disturbed, muddy soils, shallow waters | Arroyos, riverbanks, clearings in montane forests |
Elevation | 0–1000 m (0–3300 ft) | 100–1300 m (300–4300 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]
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AZ; TX; Mexico |
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.) |
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Source | FNA vol. 23, p. 156. | FNA vol. 23, p. 178. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. lateriflorus | C. buckleyi, C. parryi, C. scaberrimus, C. spectabilis var. filiformis, C. spectabilis var. parryi, C. spectabilis var. scaberrimus |
Name authority | Linnaeus: Cent. Pl. II, 6. (1756) | Sprengel: Novi Provent., 15. (1818) |
Web links |