Rhynchospora wrightiana |
Rhynchospora cephalantha |
|
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Wright's beaksedge |
bunched beaksedge |
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Habit | Plants perennial, cespitose, 10–50 cm; rhizomes absent. | Plants perennial, cespitose, 40–100(–150) cm; rhizomes absent. |
Culms | slender, ± filiform, leafy, terete to bluntly trigonous. |
arching, leafy, obscurely and convexly trigonous, multi-ribbed, slender to stoutish. |
Leaves | shorter than culm; blades spreading to ascending, ± filiform, proximally flat, 0.5–1(–1.5) mm, apex tapering, trigonous. |
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Inflorescences | spikelet clusters 1–3, loose to dense, widely spaced to close together, turbinate to hemispheric; leafy bracts setaceous, mostly exceeding spikelet clusters. |
spikelet clusters 3–several, widely spaced, often equidistant, mostly hemispheric to globose, occasionally lobed, 1–2 cm thick; bracteal leaves much exceeding subtended inflorescence. |
Spikelets | dark redbrown, lanceovoid, 2.5–3.5(–4) mm, apex acute; fertile scales ovate, 2–3.5 mm, apex acute or acuminate, rarely minutely awned. |
dark red-brown to dark brown, lanceellipsoid to ellipsoid, 4–5(–6) mm, apex acute; fertile scales elliptic, 3–3.5(–4.5) mm, apex acute, midribs 3, laterals indistinct. |
Flowers | bristles 6, of various length, mostly extending from fruit midbody to tubercle base, antrorsely barbellate. |
perianth bristles 6, reaching tubercle tip, retrorsely (rarely antrorsely) barbellate. |
Fruits | 1–2 per spikelet, (2–)2–2.5 mm; body brown with pale center, lenticular, broadly ellipsoid, 1.5–1.7 × 1.2–1.3 mm, surfaces nearly smooth or very finely cancellate; tubercle flat, triangular with short-oblong, blunttipped nose, or triangularsubulate, 0.5–0.8 mm. |
1(–2) per spikelet, 3.5–4(–4.2) mm; body brown with pale center, obovoid distal to stipe, lenticular, 2–2.3 × 1–1.5(–2) mm; tubercle triangular-subulate, (1–)1.5–2 mm, at least 0.5 mm wide at base. |
Principal | leaves overtopped by culm; blades linear, flat proximally, 1.5–3 mm wide, apex tapering, trigonous. |
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Rhynchospora wrightiana |
Rhynchospora cephalantha |
|
Phenology | Fruiting late spring–fall or all year (south). | Fruiting summer–fall. |
Habitat | Sands and peats in flatwoods, pine savannas, pond and stream banks, bogs, and seeps | Sandy silts, sands, and peats of shores, boggy streams, seeps, savannas, and savanna bogs |
Elevation | 0–200 m (0–700 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; FL; GA; MS; NC; SC; VA; Central America; West Indies
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AL; DE; FL; GA; LA; MD; MS; NC; NJ; NY; SC; TX; VA
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Discussion | The morphologic boundary between Rhynchospora wrightiana and R. fascicularis (particularly morphs of R. fascicularis referred to R. fascicularis var. distans) is difficult, as recent annotations of the material testify. It is best to consider R. wrightiana as a lower, distinctly filiformleaved entity with darker brown, shorter spikelets and shorter fruit. Kükenthal’s concept of R. wrightiana appears to include a considerable amount of R. fascicularis var. distans. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
North American plants referred to Rhynchospora axillaris (Lamarck) Britton [Phaeocephala axillare (Lamarck) House by N. L. Britton and A. Brown (1913) and J. K. Small (1933)] are actually R. cephalantha. A photograph of the type specimen of Schoenus axillaris Lamarck (from P) reveals what appears to be an immature top of S. glomeratus [R. glomerata (Linnaeus) Vahl]. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 236. | FNA vol. 23, p. 212. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. gracillima, R. distans var. gracillima, R. distans var. tenuis | R. cephalantha var. attenuata, R. cephalantha var. pleiocephala |
Name authority | Boeckeler: Flora 64: 78. (1881) | A. Gray: Ann. Lyceum Nat. Hist. New York 3: 218. (1835) |
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