Cyperus involucratus |
Cyperus pilosus |
|
---|---|---|
umbrella-plant |
fuzzy flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, annual or perennial, cespitose; stolons slender, to 5 cm × 1.5 mm. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
trigonous, 25–90 cm × 2 mm, hispidulous or glabrous on angles distally. |
Leaves | bladeless. |
flat, 10–35 cm × 3–10 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. |
spikes 1–4(–6), loosely oblong-ovoid, 2–3 × 1–2 cm; rays 3–10, 1–16 cm; 2d order rays to 3 cm; rachis hispidulous, prickles slender, 0.1–0.2 mm; bracts 3–5, ± ascending, flat, 5–35 cm × 0.5–5(–7) mm; 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. |
15–40, linear-lanceoloid, compressed, 6–12 × 1.5–2 mm; floral scales deciduous, 8–16, light brown with clear border, laterally 2–3-ribbed, ovate, 1.8–2 × 1.2–1.6 mm; apex entire, emarginate, or mucronulate, mucro at most 0.3 mm. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
anthers 0.4 mm; styles 0.6 mm; stigmas 1 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. |
brown, sessile, broadly ellipsoid, 1–1.2 × 0.5 mm, apex obtuse, apiculate, surfaces puncticulate. |
Cyperus involucratus |
Cyperus pilosus |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Rice fields, wetlands, emergent muddy shores |
Elevation | 0–100(–800) m [0–300(–2600) ft] | 0–50 m [0–160 ft] |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America] |
FL; LA; MS; SC; Asia [Introduced in North America]
|
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 pilosus was naturalized in the flora from eastern Asia, apparently early in the twentieth century. The combination of hispidulous rachis and loosely oblong-ovoid spikes is sufficient to distinguish Cyperus pilosus from any others with deciduous floral scales. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23, p. 166. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Vahl: Enum. Pl. 2: 354. (1805) |
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