Cyperus involucratus |
Cyperus grayoides |
|
---|---|---|
umbrella-plant |
Illinois flatsedge, Mohlenbrock's sedge, umbrella sedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, rhizomatous, tuberlike. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
trigonous, 5–35 cm × 0.7–1.2 mm, glabrous. |
Leaves | bladeless. |
V-shaped, 5–25 cm × 1.5–3.5 mm, slightly scabridulous on abaxial margins, midrib. |
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 loosely ± globose, 15–25 mm wide; rays 1–10 cm; rachis 1–4 mm; bracts 3–7, ascending, V-shaped, 3–20 cm × 1–3 mm; rachilla deciduous, 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. |
3–24, compressed, oblong-lanceoloid, 4–12 × 2.5–3.2 mm; floral scales deciduous, 3–9, pale reddish brown, ovate, laterally 3–5-ribbed, 2.5–3 × 2–2.4 mm, apex acute to obtuse. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
anthers 1–1.2 mm; styles 0.4–0.6 mm; stigmas 1–2 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 brown, ± stipitate, ellipsoid, 2–2.4 × 0.9–1.2 mm, apex obtuse, apiculate, surfaces glabrous, puncticulate, or papillose. |
2n | = 166. |
|
Cyperus involucratus |
Cyperus grayoides |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Sand prairies, waste places, fallow fields |
Elevation | 0–100(–800) m [0–300(–2600) ft] | 100–300 m [300–1000 ft] |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America] |
AR; IL; LA; MO; TX
|
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.) |
Of conservation concern. Cyperus grayoides is in the Center for Plant Conservation’s National Collection of Endangered Plant’s. See frontispiece. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Mohlenbrock: Brittonia 11: 255, fig. 1. (1959) |
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