Cyperus involucratus |
Cyperus distinctus |
|
---|---|---|
umbrella-plant |
swamp flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
terete, 40–60(–90)cm, glabrous. |
Leaves | bladeless. |
flat, 35–70 cm × 4–9(–12) 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. |
heads hemispheric, 10–20 mm diam.; rays 5–9(–14), 3.5–10 cm; 2d order rays 0.5–2 cm; bracts 5–10, ± horizontal, flat, 12–40(–50) cm × 2–7 mm. |
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. |
(25–)35–50(–60), ovoid, compressed, (3.5–)5–12(–14) × 2.5–3.5(–4) mm; floral scales 10–32, golden brown to brown, 2-keeled, laterally ribless, narrowly lanceolate, 2–2.2(–3) × 0.8–1.4 mm. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
stamen 1; anthers 1 mm; styles 1 mm; stigmas 0.5 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, stipitate, narrowly ellipsoid, 1.5–2 × 0.2–0.4 mm, base swollen, spongy, stipe 0.2 × 0.2–0.3 mm, apex acute, beak slender, 0.2 mm, surfaces puncticulate. |
Cyperus involucratus |
Cyperus distinctus |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Damp grasslands, roadsides, ditches |
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; GA; LA; SC; West Indies (Bahamas)
|
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.) |
The slender achenes with conspicuously swollen bases distinguish Cyperus distinctus from other species of subg. Pycnostachys. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23, p. 154. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. virens var. brittonii | |
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Steudel: Syn. Pl. Glumac. 2: 24. (1855) |
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