Cyperus floribundus |
Cyperus lancastriensis |
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Rio Grande sedge |
manyflower flatsedge, Porter's sedge |
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Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, with inconspicuous, short rhizomes scarcely visible between culm bases. |
Culms | trigonous, basally tuberous thickened, 15–40 cm × 1–2.5 mm, glabrous. |
basally cormlike, trigonous, (10–)20–80 cm × 1–3 mm, glabrous. |
Leaves | flat to V-shaped, 10–30 cm × 1–2 mm. |
inversely W-shaped, 20–70 cm × 5–11 mm, adaxial surface, margins minutely scabridulous. |
Inflorescences | spike 1, densely oblong to ellipsoid, 8–36 × 8–20 mm; rays 4–12, 10–20 cm; bracts 3–6, horizontal to ascending at 30°, V-shaped, 3–15 cm × (3–)4–5.8 mm; rachilla deciduous, wings 0.5–0.7 mm wide. |
spikes densely ellipsoid to obovoid, 2.5–4.3 × 1.5–3 cm; rays 5–10, 4–20 cm, glabrous; rachis 7–14 mm; bracts 3–8, horizontal to ascending at 45°, flat, 5–35 cm × 2.5–6 mm; rachilla persistent, wings 0.5 mm wide. |
Spikelets | (5–)20–35(–60), linear to oblong, quadrangular; 4–12(–21) × 0.7–1.2 mm, base narrowed to 0.4–1 mm; floral scales persistent, 1–3(–5), appressed, laterally whitish to reddish brown, stramineous with reddish spots, medially green, laterally 3–6-ribbed (midrib distinctly scabrid at 30X), narrowly oblong to ovate, 2.6–4.8 × 1.6–2 mm; apex rounded to ± acute, entire, with mucro 0.3–0.5 mm; sterile terminal scale involute, 0.4–0.6 mm wide, uncinate; distal floral scales with cusp 0.6–1.9. |
50–90, linear-lanceoloid to linear-subulate, ± terete-quadrangular, (11–)12–13(–15) × 1.1–1.6 mm; distal spikelet spreading or ascending; floral scales persistent, 3–6(–8), appressed, whitish green or often yellow-tinted, sometimes reddish striate, laterally 4-ribbed, ovate-lanceolate, (3.9–)4.2–4.6(–4.8) × 1.6–2 mm. |
Flowers | anthers 0.5–1.3 mm; styles 0.4–0.5 mm; stigmas 0.5–0.9 mm. |
anthers 0.7–1 mm; styles 1–1.5 mm; stigmas 2–3 mm. |
Achenes | light brown to reddish brown, sessile to slightly stipitate, narrowly ellipsoid, 1.8–2.4 × 0.6–0.8 mm, apex slightly apiculate, surfaces puncticulate. |
yellowish brown to brown, ± stipitate, conspicuously falcate, 3–4 times long as wide, oblong, 2.2–2.6 × 0.6–0.7 mm, apex obtuse, surfaces puncticulate. |
Cyperus floribundus |
Cyperus lancastriensis |
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Phenology | Fruiting mid summer–early fall (Jul–Sep). | Fruiting summer (Jul–Aug). |
Habitat | Damp, disturbed soils, croplands | Disturbed, sunny or partly shaded places in mesic or dry-mesic soils, often on riverbanks and flood plains |
Elevation | 0–1000 m (0–3300 ft) | 0–800 m (0–2600 ft) |
Distribution |
TX; Mexico |
AL; AR; DC; DE; FL; GA; KY; MD; MO; NC; NJ; OH; PA; SC; TN; VA; WV
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Discussion | Included previously in Cyperus retroflexus (or its synonym C. uniflorus), C. floribundus has a much narrower geographic range (southern Texas and northeastern Mexico) and differs in features of spikelet morphology (J. R. Carter and S. D. Jones 1997). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. uniflorus var. floribundus, C. uniflorus | C. refractus var. lancastriensis, Mariscus lancastriensis |
Name authority | (Kükenthal) J. Rich. Carter & S. D. Jones: Rhodora 99: 330. (1998) | Porter: in A. Gray, Manual ed. 5 issue 6, 555. (1867) |
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