Cyperus involucratus |
Cyperus hypopitys |
|
---|---|---|
umbrella-plant |
pine flatsedge, pinewoods sedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, rhizomatous, tending to form small clumps by basal offshoots. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
triquetrous, bulbous, thickened, (20–)30–80(–90) cm × 0.7–1.2 mm, glabrous proximally, becoming trigonous strongly scabridulous on distal angles, clothed with persistent reddish fibers at base. |
Leaves | bladeless. |
flat to V-shaped, 20–45 cm × 2–4 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. |
spike 1, loosely ovoid to ovoid-ellipsoid, (1.5–)2.5–7 × (1–)1.5–3.5 cm; rays (1–)2–4, to 6 cm; 2d order rays rarely present, to 2 cm; 3d order rays absent; bracts (2–) 3, ± horizontal, 1–15(–21) cm × 0.4–3.5 mm; rachilla deciduous, wings hyaline, 0.3–0.4 mm wide. |
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–)8–26, reddish to reddish brown, linear, compressed-quadrangular, 8–18 × (2.4–)2.8–4 mm; floral scales deciduous, 6–16, laterally reddish, medially green, occasionally red-glandular, laterally strongly 3(–4)-ribbed, medially punctate, 1–3-ribbed, ovate-lanceolate, (2.6–)2.8–3.3 × (1.4–)1.6–1.8(–2) mm, apex weakly 3-dentate, mucronulate, with tuft of crystalline prickles, medially glabrous. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
anthers 0.8–1.1 mm; styles 1–1.4 mm; stigmas 1–1.4 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. |
brownish, stipitate, ellipsoid, 1.6–2 × (0.7–)0.9–1 mm, base whitish, stipe to 0.1–0.2 mm, apex obtuse, slightly apiculate, surfaces papillose. |
Cyperus involucratus |
Cyperus hypopitys |
|
Phenology | Fruiting early summer–fall. | Fruiting late summer–early fall. |
Habitat | Damp, disturbed soils, ditches, stream banks | Canyons in pine forests |
Elevation | 0–100(–800) m [0–300(–2600) ft] | 500–1500 m [1600–4900 ft] |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America] |
AZ; Mexico (Chihuahua, Durango, Sinaloa, Sonora) |
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 hypopitys can be recognized by the combination of reddish floral scales and sharp-angled culms. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23, p. 178. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | G. C. Tucker: Syst. Bot. Monogr. 43: 129, fig. 54. (1994) |
Web links |