Cyperus involucratus |
Cyperus microiria |
|
---|---|---|
umbrella flatsedge, umbrella-plant |
lesser rice-field flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, annual, cespitose. |
Culms | trigonous, 30–150 cm × 1–5(–8) mm. |
trigonous, (5–)20–60 cm × (0.2–)0.6–2.4 mm, glabrous. |
Leaves | bladeless. |
(1–)3–4, V-shaped, 15–40 cm × 3–6 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 2–5(–8), oblong to ovoid, 2–10 cm × 3–12 mm; rays 4–8, to 11 cm; bracts (4–)5(–7), ascending at 45°, V-shaped, (1.5–)8–30(–50) cm × 1–6 mm; rachilla persistent, wingless (successive floral scales 1.1–1.5 mm apart). |
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. |
10–30, spreading, compressed, linear, 4–20 × 1.5–2.1 mm; floral scales deciduous, (2–)6–26, laterally brown to golden brown, edges clear, medially green, 5-ribbed, outermost ribs more noticeable than others, obovate to nearly orbiculate, 1.3–1.8 × 1.2–1.8 mm, margins emarginate, apex mucronulate, mucro 0.2–0.25 mm. |
Flowers | stamens 3; anthers 0.7–1 mm; styles 0.5–1 mm; stigmas 0.6–1 mm. |
stamens 2(–3); anthers (0.2–)0.3–0.4 mm, tips of connectives reddish, less than 0.1 mm; styles less than 0.1 mm; stigmas 0.2–0.4(–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, slightly stipitate, obovoid, 1.2–1.4(–1.5) × 0.5–0.7 mm, apex apiculate, surfaces puncticulate. |
Cyperus involucratus |
Cyperus microiria |
|
Phenology | Fruiting early summer–fall. | Fruiting summer. |
Habitat | Damp, disturbed soils, ditches, stream banks | Disturbed soils |
Elevation | 0–100(–800) m (0–300(–2600) ft) | 0–100 m (0–300 ft) |
Distribution |
CA; FL; LA; TX; e Africa [Introduced in North America]
|
CT; KY; MA; NJ; NY; OH; PA; e Asia [Introduced in North America] |
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 name Cyperus amuricus Maximowicz has been misapplied to C. microiria by some American authors (e.g., M. V. McGivney 1938). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 150. | FNA vol. 23, p. 166. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. iria var. microiria, C. iria var. parviflorus, C. iria var. rectangularis | |
Name authority | Rottbøll: Descr. Pl. Rar., 22. (1772) | Steudel: Syn. Pl. Glumac. 2: 23. (1855) |
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