Cyperus lanceolatus |
Cyperus iria |
|
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epiphytic flatsedge |
rice-field flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, annual, cespitose. |
Culms | trigonous, compressed, 15–75 cm × 0.5–3 mm, glabrous. |
trigonous, (5–)20–60 cm × (0.2–) 0.6–2.4 mm, glabrous. |
Leaves | 1–3, 5–30 cm × 1–2 mm. |
(1–)3–4, V-shaped, 15–40 cm × 3–6 mm. |
Inflorescences | spikes 1(–2), ovoid, 5–23 × 9–21 mm; rays 2–3(–4), 0–15 mm; if rays absent, head single, compact, sessile, (12–)15–20 mm diam.; bracts 2–3, horizontal to vertical, 2–14 cm × 0.5–3.5 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 0.7–0.9 mm apart). |
Spikelets | 1–6, oblong-lanceoloid, 5–26 × 2–3 mm; floral scales 12–54, closely imbricate, laterally yellowish brown, medially pale brown, occasionally greenish, laterally 1-ribbed, medially 3-ribbed, distinctly 2-keeled basally, ovate, 1.8–2.6 × 1.4–1.7 mm, apex obtuse. |
10–30, compressed, linear to ellipsoid, 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 with mucro 0.05–0.12 mm. |
Flowers | stamens 2; anthers 0.4–0.5 mm, connectives not prolonged; styles 0.3–1 mm; stigmas 0.6–0.8(–1) mm. |
stamens 2(–3); anthers (0.2–)0.3–0.4 mm, connective tips reddish, less than 0.1 mm; styles less than 0.1 mm; stigmas 0.2–0.4 mm. |
Achenes | brown, network of ridges forming isodiametric or square cells, stipitate, obovoid to ellipsoid, 1.1–1.3 × (0.5–)0.6 mm, apex acute to broadly rounded, surfaces minutely punctate or finely papillose. |
brown, slightly stipitate, obovoid, 1.2–1.4 × 0.5–0.7 mm, apex apiculate, surfaces puncticulate. |
Cyperus lanceolatus |
Cyperus iria |
|
Phenology | Fruiting summer. | Fruiting summer–fall (Jul–Oct). |
Habitat | Marshes | Damp to moderately dry, disturbed soils |
Elevation | 0–100 m (0–300 ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; FL; GA; LA; TX; Mexico; Central America; South America; Africa
|
AL; AR; CA; CT; FL; GA; IL; LA; MD; MO; MS; NC; NY; OK; SC; TN; TX; VA; WV; Mexico; Central America; South America; Asia; Africa; Australia [Introduced in North America]
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Discussion | Cyperus iria was first recorded in the New World from the southeastern United States in the 1840s. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 162. | FNA vol. 23, p. 166. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. densus, C. humboldtianus, C. lanceolatus var. compositus, Pycreus densus | |
Name authority | Poiret: in J. Lamarck et al., Encycl. 7: 245. (1806) | Linnaeus: Sp. Pl. 1: 45. (1753) |
Web links |