Cyperus difformis |
Cyperus ligularis |
|
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Asian flatsedge, smallflower umbrella sedge, variable flatsedge |
Alabama swamp flatsedge |
|
Habit | Herbs, annual, cespitose. | Herbs, perennial, solitary or cespitose, rhizomatous, coarse. |
Culms | 1–15, trigonous, 7–30 cm × 1.2–2.5 mm, soft (flattened in pressing), glabrous. |
trigonous, (30–)60–130 cm × 1–4(–9) mm, densely papillose, otherwise glabrous. |
Leaves | 2–7, flat, (2–)7–22 cm × 2.2–4 mm. |
with cross ribs prominent, V-shaped, 30–100 cm × 5–13(–20) mm, margins, keel incisive with brownish prickles, papillose throughout, margins and midribs harshly scabrid. |
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. |
spikes 3–7, densely oblong-cylindric to ± globose, 10–28(–35) × 8–12(–15) mm; rays 5–12, 1–16 cm, densely papillose; bracts 5–12, ascending at 30–75°, flat to V-shaped, 4–50(–90) cm × 1–15 mm; rachilla deciduous, wings persistent, (0.2–)0.3–0.5(–0.6) 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. |
20–80, oblong-ellipsoid, ± terete, slightly compressed, 3–7 × 1–2(–2.7) mm; distal spikelets spreading or ascending; floral scales (2–)4–7, appressed, clear to brownish, reddish streaked, medially green, 9–11-ribbed, ovate, (2–)2.5–3.3 × 1.2–2.3 mm, apex acute, mucronate. |
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 0.6–0.8 mm, styles 0.5–1 mm; stigmas 1–2.3 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, slightly stipitate, obovoid to broadly ellipsoid, (1.2–)1.5–1.6(–1.7) × 0.6–0.8 mm, apex apiculate, surfaces puncticulate. |
Cyperus difformis |
Cyperus ligularis |
|
Phenology | Fruiting summer. | Fruiting throughout the year. |
Habitat | Disturbed, muddy soils, shallow waters | Beaches, brackish marshes, mangrove swamps, disturbed soils, ditches, riverbanks, coastal croplands |
Elevation | 0–1000 m (0–3300 ft) | 0 m (0 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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FL; Mexico; Central America; South America; w Africa
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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.) |
The papillose culms, rays, and leaves of Cyperus ligularis distinguish it from all other North American species of Cyperus. Reports of Cyperus ligularis from California (G. C. Tucker 1993b) were based on specimens of C. owanii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 156. | FNA vol. 23, p. 190. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. lateriflorus | Mariscus rufus |
Name authority | Linnaeus: Cent. Pl. II, 6. (1756) | Linnaeus: Syst. Nat. ed. 10, 2: 867. (1759) |
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