Cyperus haspan |
Cyperus involucratus |
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haspan flatsedge |
umbrella flatsedge, umbrella-plant |
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Habit | Herbs, perennial, cespitose, shortly rhizomatous. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, (2–)25–60(–100) cm × 1–4 mm, soft (flattened in drying), glabrous. |
trigonous, 30–150 cm × 1–5(–8) mm. |
Leaves | usually reduced to sheaths, occasionally with blades, flat to V-shaped, (3–)10–30 cm × (1–)2.5–5 mm. |
bladeless. |
Inflorescences | heads loosely digitate; rays (5–)10–12(–15), 1–15(–20) cm; 2d order rays usually present, (1–)6–12(–25) mm; 3d order rays sometimes present, 1–6 mm; bracts 2(–3), horizontal to ascending at 30–60°, longer (3–)6–18 cm × 2–4 mm, shorter (0.5–)2.5–6.5 cm × 1–2(–3) mm. |
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. |
Spikelets | 1–15, linear-lanceoloid, ± compressed-quadrangular, 3–18 × 1–1.6 mm; floral scales 10–20(–40), laterally reddish to greenish brown, dull, often clear-edged, medially greenish, laterally 1-ribbed, medially 1-ribbed, oblong to obovate, 1–1.5(–1.9) × 0.8–1 mm, apex mucronate, glabrous except for cluster of crystalline prickles at apex. |
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. |
Flowers | stamens 3; anthers 0.3–0.5 mm; styles 0.4–0.9 mm; stigmas 0.5–0.8(–1.3) mm. |
stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
Achenes | white or reddish brown, stipitate, globose to obovoid or ellipsoid, 0.5–0.6(–0.7) × 0.3–0.4(–0.5) mm, base nearly cuneate, stipe 0.1 × 0.1–0.2 mm, apex obtuse to acute, apiculate or entire, surfaces granular to papillose. |
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. |
Cyperus haspan |
Cyperus involucratus |
|
Phenology | Fruiting summer. | Fruiting early summer–fall. |
Habitat | Swales between dunes, marshes, pond shores | Damp, disturbed soils, ditches, stream banks |
Elevation | 0–200 m (0–700 ft) | 0–100(–800) m (0–300(–2600) ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; VA; Mexico; Central America; South America; Asia; Africa; Australia
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CA; FL; LA; TX; e Africa [Introduced in North America]
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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.) |
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Source | FNA vol. 23, p. 151. | FNA vol. 23, p. 150. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. autumnalis, C. haspan subsp. juncoides, C. haspan var. americanus, C. juncoides | |
Name authority | Linnaeus: Sp. Pl. 1: 45. (1753) | Rottbøll: Descr. Pl. Rar., 22. (1772) |
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