Cyperus involucratus |
Cyperus elegans |
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umbrella-plant |
royal flatsedge, sticky flatsedge |
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Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, shortly rhizomatous, coarse, viscous. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
round to roundly trigonous, 15–80 cm × 2–4 mm, glabrous. |
Leaves | bladeless. |
adaxial face concave, becoming trigonous apically, 15–75 cm × 1–4 mm, margins involute. |
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. |
spikes ovoid, 10–20 mm wide; rays 3–8(–10), 0.5–12 cm; 2d order rays 0–3, 1–3 cm; bracts 3–7, horizontal to vertical, 2.5–5.5 cm × 1–4 mm, margins involute; 2d order bracts 0–3, 1–3 cm; rachilla persistent, 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. |
3–20(–30), beige to greenish or reddish brown, strongly compressed, oblong-ellipsoid to oblong-lanceoloid, 3–15 × 2.5–3.5 mm; floral scales deciduous, 6–22, laterally pale greenish white to stramineous or reddish brown, medially pale green to yellowish green, laterally 2-ribbed, medially 3–5-ribbed, broadly ovate, (2–)2.8–3.6 × 2.4–2.6 mm, apex with slightly excurved mucro 0.2–0.3 mm, apically scabrid. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
anthers 0.6–1.4 mm; styles 1.2–1.5 mm; stigmas 1–1.5(–3) 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. |
dark reddish brown to black, stipitate, obovoid, faces concave, flat or subtly convex, (1.4–)1.8–2 × 0.9–1 mm, base cuneate, stipe (sometimes absent) spongy, 0.1–0.2 × 0.2–0.4 mm, apex truncate, apiculate, surfaces coarsely papillose. |
Cyperus involucratus |
Cyperus elegans |
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Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Ditches, damp pastures, pond shores, riverbanks |
Elevation | 0–100(–800) m [0–300(–2600) ft] | 0–500 m [0–1600 ft] |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America] |
FL; LA; NM; TX; Mexico; Central America; South 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. 150. | FNA vol. 23, p. 172. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. trachynotus | |
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Linnaeus: Sp. Pl. 1: 45. (1753) |
Web links |