Cyperus haspan |
Cyperus iria |
|
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haspan flatsedge |
rice-field flatsedge |
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Habit | Herbs, perennial, cespitose, shortly rhizomatous. | Herbs, annual, cespitose. |
Culms | trigonous, (2–)25–60(–100) cm × 1–4 mm, soft (flattened in drying), glabrous. |
trigonous, (5–)20–60 cm × (0.2–) 0.6–2.4 mm, glabrous. |
Leaves | usually reduced to sheaths, occasionally with blades, flat to V-shaped, (3–)10–30 cm × (1–)2.5–5 mm. |
(1–)3–4, V-shaped, 15–40 cm × 3–6 mm. |
Inflorescences | heads loosely digitate; rays (5–)10–12(–15), 1–15(–20) cm; 2d order rays usually present, (1–)6–12(–25) mm; 3d order rays sometimes present, 1–6 mm; bracts 2(–3), horizontal to ascending at 30–60°, longer (3–)6–18 cm × 2–4 mm, shorter (0.5–)2.5–6.5 cm × 1–2(–3) 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 | 1–15, linear-lanceoloid, ± compressed-quadrangular, 3–18 × 1–1.6 mm; floral scales 10–20(–40), laterally reddish to greenish brown, dull, often clear-edged, medially greenish, laterally 1-ribbed, medially 1-ribbed, oblong to obovate, 1–1.5(–1.9) × 0.8–1 mm, apex mucronate, glabrous except for cluster of crystalline prickles at apex. |
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 3; anthers 0.3–0.5 mm; styles 0.4–0.9 mm; stigmas 0.5–0.8(–1.3) 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 | white or reddish brown, stipitate, globose to obovoid or ellipsoid, 0.5–0.6(–0.7) × 0.3–0.4(–0.5) mm, base nearly cuneate, stipe 0.1 × 0.1–0.2 mm, apex obtuse to acute, apiculate or entire, surfaces granular to papillose. |
brown, slightly stipitate, obovoid, 1.2–1.4 × 0.5–0.7 mm, apex apiculate, surfaces puncticulate. |
Cyperus haspan |
Cyperus iria |
|
Phenology | Fruiting summer. | Fruiting summer–fall (Jul–Oct). |
Habitat | Swales between dunes, marshes, pond shores | Damp to moderately dry, disturbed soils |
Elevation | 0–200 m (0–700 ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; VA; Mexico; Central America; South America; Asia; Africa; Australia
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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. 151. | FNA vol. 23, p. 166. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. autumnalis, C. haspan subsp. juncoides, C. haspan var. americanus, C. juncoides | |
Name authority | Linnaeus: Sp. Pl. 1: 45. (1753) | Linnaeus: Sp. Pl. 1: 45. (1753) |
Web links |