Cyperus involucratus |
Cyperus pseudovegetus |
|
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umbrella-plant |
marsh flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose; rhizomes upright, 5–8 mm diam., indurate. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
trigonous, 30–50(–80) cm × 1.8–2.5 mm, glabrous. |
Leaves | bladeless. |
4–7(–10), V-shaped, (20–)40–60 cm × 4.5–8 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 dense, hemispheric, 7–15(–18) mm diam; or if rays absent, heads dense, irregularly lobate, 2–3.5 cm diam.; rays 3–6, 1–30 mm; 2d order rays infrequently present, to 5 mm; bracts (5–)10–15(–40), horizontal to ascending at 30(–45)°, V-shaped, 6–30(–40) cm × 5–8(–10) 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. |
40–100, greenish white, flattened, ovoid, 3.5–5 × 3–4 mm; floral scales (8–)12–16, uniformly light greenish to light brown, laterally 1-ribbed, medially indistinctly 3-ribbed, basally 2-keeled, oblong-spatulate, widest at or above median, 2–2.5 × (0.7–)1–1.2 mm, apex minutely mucronate, scabridulous, infrequently glabrous. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
stamen 1; anthers oblong, 0.7–1 mm, connective apex subulate, prolonged 0.1–0.2 mm; styles thick, confluent with apex of, and persistent on, achene, 0.5–0.8 mm; stigmas 0.6–1 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, stipitate, linear, slightly curved, 1.2–1.4 × 0.2(–0.3) mm, base whitish, stipe spongy, 0.1–0.2 × 0.2 mm, apex acute, surfaces papillose. |
Cyperus involucratus |
Cyperus pseudovegetus |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Damp places |
Elevation | 0–100(–800) m [0–300(–2600) ft] | 0–200 m [0–700 ft] |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America] |
AL; AR; DC; DE; FL; GA; IL; IN; KS; KY; LA; MA; MD; MO; NC; NJ; OK; SC; TN; TX; VA
|
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 pseudovegetus has been called “Cyperus vegetus Willd.” (M. L. Fernald 1950). The var. megalanthus Kükenthal of eastern Mexico and Central America recognized by M. F. Denton (1978b) is now considered a distinct species, C. megalanthus (Kükenthal) G. C. Tucker (see G. C. Tucker 1994). Cyperus pseudovegetus is introduced in Massachusetts. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23, p. 156. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Steudel: Syn. Pl. Glumac. 2: 24. (1855) |
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