Cyperus lanceolatus |
Cyperus retrofractus |
|
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epiphytic flatsedge |
rough flatsedge |
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Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose. |
Culms | trigonous, compressed, 15–75 cm × 0.5–3 mm, glabrous. |
with cormlike bases, sharply trigonous, 25–90 cm, glabrous proximally, minutely scabridulous distally. |
Leaves | 1–3, 5–30 cm × 1–2 mm. |
V-shaped, 14–40 cm × 3.5–8 mm, (pubescent on adaxial side of midrib). |
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, obtrulloid to obdeltoid (broadest near apex, nearly as long as wide), 20–28(–34) × (12–)15–30 mm; rays 4–13, (1–)4–24 cm (longest ray shorter than bracts), glabrous; bracts 3–12, ascending at 30–45°, flat, 3–25 cm × 3–7 mm; rachilla persistent, wings 0.4–0.6 mm wide, covering 3/4 of mature achene. |
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. |
30–50, proximal one reflexed, distal ones divaricate, linear-lanceoloid, ± terete, (6.5–) 8–10(–17) × 0.5–0.7 mm; floral scales persistent, 3–6(–8), appressed, stramineous (suffused with reddish purple), 4–5-ribbed laterally, ovate-lanceolate, (4–)4.4–4.9(–5.4) × 1.3–1.5 mm; terminal scale not spinose, apex straight, excurved mucronate, or cuspidate. |
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 0.7–1.2 mm; styles 1.5–2 mm; stigmas 2–2.5 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 brownish black, narrowly oblong, (2.2–)2.5–3 × 0.6–0.7 mm, base cuneate, apex obtuse, apiculate, surfaces puncticulate. |
Cyperus lanceolatus |
Cyperus retrofractus |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Marshes | Roadsides, pastures, disturbed sites in sandy or clayey soils |
Elevation | 0–100 m (0–300 ft) | 0–300 m (0–1000 ft) |
Distribution |
AL; FL; GA; LA; TX; Mexico; Central America; South America; Africa
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AL; AR; DC; DE; GA; KY; MO; NC; NJ; OH; PA; SC; TN; VA
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Discussion | For information concerning nomenclature of Cyperus retrofractus, see J. R. Carter and C. E. Jarvis (1986). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 162. | FNA vol. 23, p. 180. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. densus, C. humboldtianus, C. lanceolatus var. compositus, Pycreus densus | Scirpus retrofractus, C. dipsaciformis, C. retrofractus var. dipsaciformis, Mariscus retrofractus |
Name authority | Poiret: in J. Lamarck et al., Encycl. 7: 245. (1806) | (Linnaeus) Torrey: in J. Carey, Carices North. U.S., 519. (1847) |
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