Cyperus involucratus |
Cyperus distans |
|
---|---|---|
umbrella flatsedge, umbrella-plant |
Piedmont flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, rhizomatous. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
single or close together, trigonous, (10–)40–80(–120) cm × 1.2–2.5(–5) mm, glabrous. |
Leaves | bladeless. |
2–5, pleated, (10–)20–50(–90) cm × 2–5(–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(–7), loose, broadly ovoid to ovoid-pyramidal, 25–35 × 25–35 mm; rays (4–)5–6(–8), (1–)3–8(–16) cm, glabrous; 2d order rays (0–)1–5, 5–15(–50) mm; bracts 4–7, ascending at 30–45°, pleated, (5–)20–40(–60) × (2–)3–8(–11) mm; 2d order bracts 1–4 per ray, 5–10(–30) × 0.5–1 mm, scabridulous; rachilla persistent, wingless (or very narrowly winged, not clasping achene). |
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. |
(10–)20–35(–45), seemingly flattened proximally from spreading floral scales, becoming terete apically, linear, (10–)13–18(–25) × 1.2–1.5(–1.6) mm; floral scales deciduous, (10–)12–20(–25), laterally light reddish brown to dark red, medially greenish, laterally ribless, medially 3–5-ribbed, oblong-ovate, 1.7–2(–2.4) × 0.9–1.2 mm, apex obtuse, barely reaching next scale, apex entire, emarginate, 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 0.4–0.5 mm; styles 0.3–0.6 mm; stigmas 1–1.8(–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, narrowly oblong, (1.3–)1.4–1.6(–1.7) × (0.3–)0.4–0.5 mm, base cuneate to ± stipelike, apex acute, not apiculate, surfaces papillose. |
Cyperus involucratus |
Cyperus distans |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Marshes |
Elevation | 0–100(–800) m (0–300(–2600) ft) | 0 m (0 ft) |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America]
|
FL; NC; Mexico; South America; West Indies (Dominican Republic south through the Lesser Antilles); Asia; Africa |
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.) |
|
Source | FNA vol. 23, p. 150. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. elatus | |
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Linnaeus f.: Suppl. Pl., 103. (1782) |
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