Cyperus lanceolatus |
Cyperus refractus |
|
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epiphytic flatsedge |
reflexed flatsedge |
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Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, with inconspicuous, short rhizomes scarcely visible between culm bases. |
Culms | trigonous, compressed, 15–75 cm × 0.5–3 mm, glabrous. |
basally cormlike, trigonous, 30–100 cm × 2–4 mm, glabrous. |
Leaves | 1–3, 5–30 cm × 1–2 mm. |
V-shaped to flat, 20–70 cm × 3–8 mm, adaxial surface, margins minutely scabridulous. |
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 loose, broadly ellipsoid to ovoid, 4–7 × 2–6 cm; rays 6–13(–16), 4–25 cm, glabrous; rachis 1.5–3 cm; bracts 3–6, horizontal to ascending at 30°, flat, 5–35 cm × 2.5–6 mm; rachilla persistent, wings 0.4–0.5 mm wide. |
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. |
(13–)20–60(–74), linear, ± terete, (11–)13–25(–28) × 1.2–1.5 mm; distal spikelets spreading or ascending; floral scales persistent, (2–)3–6, stramineous, red-purple striate, laterally 3–5-ribbed, ovate-lanceolate, 4.5–5.3 × 1.2–1.5 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. |
anthers 1–1.5 mm; styles 1.5 mm; stigmas 1.5 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 to purplish brown, oblong-linear (5–6 times long as wide), 2.6–3 × 0.5–0.6 mm, base cuneate, apex obtuse, surfaces puncticulate. |
Cyperus lanceolatus |
Cyperus refractus |
|
Phenology | Fruiting summer. | Fruiting summer (Jul–Aug). |
Habitat | Marshes | Sandy riverbanks, gravelly roadsides, pastures, disturbed places |
Elevation | 0–100 m (0–300 ft) | 20–300 m (100–1000 ft) |
Distribution |
AL; FL; GA; LA; TX; Mexico; Central America; South America; Africa
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AL; AR; DC; GA; MD; MO; NC; PA; SC; TN; VA; WV |
Discussion | Cyperus refractus is often mistaken for C. strigosus, which has shorter anthers (0.4–0.5 mm) and spreading, ± deciduous floral scales. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 162. | FNA vol. 23, p. 182. |
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) | Engelmann ex Boeckeler: Linnaea 36: 369. 1870, based on Cyperus refrofractus Engelmann ex Steudel, Syn. Pl. Glumac. 2: 47. 1855, not (Linnaeus) Torrey (1848) |
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