Rhynchospora wrightiana |
Rhynchospora colorata |
|
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Wright's beaksedge |
starrush whitetop, white star sedge |
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Habit | Plants perennial, cespitose, 10–50 cm; rhizomes absent. | Plants perennial, cespitose or solitary, to 70 cm; rhizomes slender, scaly, to 2 mm thick. |
Culms | slender, ± filiform, leafy, terete to bluntly trigonous. |
erect, slender, leafy-based, trigonous, several-ribbed. |
Leaves | shorter than culm; blades spreading to ascending, ± filiform, proximally flat, 0.5–1(–1.5) mm, apex tapering, trigonous. |
spreading to erect, overtopped by culm; blades narrowly linear, proximally flattened, 0.5–3 mm wide, apex tapering, trigonous. |
Inflorescences | spikelet clusters 1–3, loose to dense, widely spaced to close together, turbinate to hemispheric; leafy bracts setaceous, mostly exceeding spikelet clusters. |
terminal, solitary, headlike, dense, white, leafy-involucrate; involucral bracts several, flaring to recurved, white from broadened base nearly to median, then green to tapered tip, longer bracts 13 cm × 2–7 mm. |
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. |
white, ovoid, 5–7 mm, apex acute; fertile scales many, boatshaped, sharply curvedkeeled, 3–4(–5) mm, apex acute or blunt. |
Flowers | bristles 6, of various length, mostly extending from fruit midbody to tubercle base, antrorsely barbellate. |
perianth absent. |
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. |
several per spikelet, 1.5–1.7(–2) mm; body yellow to mahogany, broadly pyriformobovoid, tumidly lenticular, 1 × 0.5–0.7 mm, widest at apex, margins thickened, interrupted at base of tubercle; surfaces transversely undulaterugose, ridges contiguous, of shortlinear papillae; tubercle broadly triangular, 0.5–0.6 mm, graycrustaceous, apex short acuminate. |
2n | = 12. |
|
Rhynchospora wrightiana |
Rhynchospora colorata |
|
Phenology | Fruiting late spring–fall or all year (south). | Fruiting late spring–summer. |
Habitat | Sands and peats in flatwoods, pine savannas, pond and stream banks, bogs, and seeps | Sands, peats, and silt of interdunal swales, shores, meadowy swales, and marsh edges, sometimes fens, usually on circumneutral or basic substrates |
Elevation | 0–200 m (0–700 ft) | 0–300 m (0–1000 ft) |
Distribution |
AL; FL; GA; MS; NC; SC; VA; Central America; West Indies
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AL; AR; FL; GA; LA; MS; NC; SC; TX; VA; Mexico; Central America; West Indies; South America (French Guiana)
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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.) |
Rhynchospora colorata is a slender and clonal version of R. latifolia, with a distinct preference for more basic substrates; involucral bracts are very slender and have a longer portion of green, usually reaching well proximal to midbract. See also 16. Rhynchospora latifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 236. | FNA vol. 23, p. 215. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. gracillima, R. distans var. gracillima, R. distans var. tenuis | Schoenus coloratus, Dichromena cephalotes, Dichromena colorata, Dichromena leucocephala, R. drummondiana, Scirpus cephalotes |
Name authority | Boeckeler: Flora 64: 78. (1881) | (Linnaeus) H. Pfeiffer: Repert. Spec. Nov. Regni Veg. 38: 89. (1935) |
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