Cyperus involucratus |
Cyperus squarrosus |
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umbrella flatsedge, umbrella-plant |
awn cyperus, awn flatsedge, bearded flatsedge |
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Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, annual, cespitose, with fibrous roots. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
1–20, trigonous, 2–16 cm × 0.5–0.8 mm, glabrous. |
Leaves | bladeless. |
1–3, flat to V-shaped, (1–)5–10(–15) × 0.5–2.5 mm. |
Inflorescences | heads digitate, 15–30(–36) mm diam.; rays (14–)20–22, (2–)5–12(–20) cm; 2d order rays 0.3–3(–4) cm; 3d order rays sometimes present, 0.3–2.5 cm; bracts (4–)18–22, ± horizontal, flat, 15–27 cm × (1.5–)8–12 mm. |
spike 1, loosely to densely ovoid to oblong, 6–20(–40) × 9–15(–20) mm; rays absent or 1–3(–6), 4–40 mm; bracts (1–)2–4, longest ± erect, V-shaped, 1–15 cm × 0.5–3 mm; rachilla ± deciduous, wingless. |
Spikelets | 8–20, ovoid to linear-lanceoloid, compressed, 5–25 × 1.5–2 mm; floral scales 8–28, laterally whitish or light brown, ± hyaline, medially light brown, laterally ribless, medially 3-ribbed, 2-keeled in proximal 30–60%, deltate-ovate, 1.6–2.4 × (1–)1.2–1.5(–1.7) mm, apex acute. |
(2–)6–20(–40), greenish to reddish brown, somewhat compressed, ovoid-lanceoloid to oblong, 2.5–10(–20) × 1.3–2.2 mm (excluding awns); floral scales deciduous, (4–)10–20(–34), greenish to stramineous or brownish red laterally, greenish medially, (5–)7–9(–11)-ribbed nearly to margins, oblong-lanceolate, (1.2–)1.3–1.8(–2.2) × (0.5–)0.7–0.8(–1) mm, apex cuspidate, excurved awn additional 0.5–1(–1.3) mm. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
stamen 1, filaments 1.5 mm; anthers oblong, 0.2–0.3 mm, connective apex reddish, minute; styles 0.3–0.5 mm; stigmas 0.4–0.7 mm. |
Achenes | brown, sessile or stipitate, broadly ellipsoid, 0.6–0.8 × 0.4–0.6 mm, stipe if present to 0.1 mm, apex obtuse, apiculate, surfaces puncticulate. |
light brown to nearly black, stipitate, obovoid (occasionally linear-spatulate or linear oblong, infrequently constricted in middle), 0.7–0.8(–1.1) × (0.2–)0.3–0.4(–0.5) mm, stipe 0.05–0.1 × 0.1 mm, apex truncate, apiculate, surfaces papillose. |
Cyperus involucratus |
Cyperus squarrosus |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Moist, disturbed soils, gravelly roadsides, flood plains, edges of puddles, muddy places |
Elevation | 0–100(–800) m (0–300(–2600) ft) | 0–2500 m (0–8200 ft) |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America]
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AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; ON; QC; Mexico; Central America; South America; West Indies; Bermuda; Eurasia; Africa; Atlantic Islands; Indian Ocean Islands; Pacific Islands; Australia
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Discussion | Cyperus involucratus has been collected in New York (R. S. Mitchell and G. C. Tucker 1997). Cyperus involucratus is widely cultivated as a water plant in greenhouses and outdoors in warm-temperate or tropical climates. It has long been misidentified in the flora as C. alternifolius Linnaeus, an endemic of Madagascar (G. C. Tucker 1983). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus squarrosus can be recognized by its small size and annual habit combined with its oblong-lanceolate floral scales bearing five to eleven conspicuous ribs and excurved awns. Some collections have been misidentified as C. acuminatus, an annual species of subg. Pycnostachys that has ovate-lanceolate, three-ribbed floral scales and digitately clustered spikelets. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23, p. 165. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | Chlorocyperus inflexus, C. aristatus, C. aristatus var. inflexus, C. aristatus var. runyonii, C. inflexus, Dichostylis aristata, Mariscus squarrosus | |
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Linnaeus: Cent. Pl. II, 6. (1756) |
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