Cyperus floribundus |
Cyperus dentatus |
|
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Rio Grande sedge |
tooth flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, rhizomatous; stolons tuberiferous, 1–10 cm. |
Culms | trigonous, basally tuberous thickened, 15–40 cm × 1–2.5 mm, glabrous. |
trigonous, 8–50 cm × 1–3 mm. |
Leaves | flat to V-shaped, 10–30 cm × 1–2 mm. |
flat or V-shaped, 10–40 cm × 2–5 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. |
heads digitate, 8–18 mm diam.; rays 4–9, 1–8 cm; 2d order rays 0.5–2 cm; bracts 3–5, ± horizontal, flat, 1–20 cm × 1–4 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. |
commonly proliferous, 2–6, linear to oblong, compressed, 3–24 × 2–2.5 mm; floral scales 3–20(–50), reddish brown, laterally 1–3-ribbed, ovate, 2–2.5 × 1.5–2 mm. |
Flowers | anthers 0.5–1.3 mm; styles 0.4–0.5 mm; stigmas 0.5–0.9 mm. |
stamens 3; anthers 1.5 mm; styles 1 mm; stigmas 1.5 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. |
reddish brown, sessile, obovoid, 0.8–1 × 0.4–0.5 mm, apex obtuse, scarcely apiculate, surfaces glabrous. |
Cyperus floribundus |
Cyperus dentatus |
|
Phenology | Fruiting mid summer–early fall (Jul–Sep). | Fruiting summer. |
Habitat | Damp, disturbed soils, croplands | Emergent sandy, peaty, or gravelly shorelines |
Elevation | 0–1000 m (0–3300 ft) | 0–600 m (0–2000 ft) |
Distribution |
TX; Mexico |
CT; DC; DE; IN; MA; MD; ME; NC; NH; NY; PA; RI; SC; TN; VA; VT; NB; NS; ON; QC
|
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.) |
The report of Cyperus dentatus from West Virginia (M. V. McGivney 1938) is erroneous; the cited specimen was from New Jersey (Gutenberg s.n. 1886, US) (M. Strong, pers. comm.). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 151. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. uniflorus var. floribundus, C. uniflorus | |
Name authority | (Kükenthal) J. Rich. Carter & S. D. Jones: Rhodora 99: 330. (1998) | Torrey: Fl. N. Middle United States 1: 61. (1824) |
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