Cyperus floribundus |
Cyperus lanceolatus |
|
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Rio Grande sedge |
epiphytic flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, basally tuberous thickened, 15–40 cm × 1–2.5 mm, glabrous. |
trigonous, compressed, 15–75 cm × 0.5–3 mm, glabrous. |
Leaves | flat to V-shaped, 10–30 cm × 1–2 mm. |
1–3, 5–30 cm × 1–2 mm. |
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 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. |
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. |
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. |
Flowers | anthers 0.5–1.3 mm; styles 0.4–0.5 mm; stigmas 0.5–0.9 mm. |
stamens 2; anthers 0.4–0.5 mm, connectives not prolonged; styles 0.3–1 mm; stigmas 0.6–0.8(–1) 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. |
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. |
Cyperus floribundus |
Cyperus lanceolatus |
|
Phenology | Fruiting mid summer–early fall (Jul–Sep). | Fruiting summer. |
Habitat | Damp, disturbed soils, croplands | Marshes |
Elevation | 0–1000 m (0–3300 ft) | 0–100 m (0–300 ft) |
Distribution |
TX; Mexico |
AL; FL; GA; LA; TX; Mexico; Central America; South America; Africa
|
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.) |
|
Source | FNA vol. 23. | FNA vol. 23, p. 162. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycreus |
Sibling taxa | ||
Synonyms | C. uniflorus var. floribundus, C. uniflorus | C. densus, C. humboldtianus, C. lanceolatus var. compositus, Pycreus densus |
Name authority | (Kükenthal) J. Rich. Carter & S. D. Jones: Rhodora 99: 330. (1998) | Poiret: in J. Lamarck et al., Encycl. 7: 245. (1806) |
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