Rhynchospora fascicularis |
Rhynchospora alba |
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fascicled beaksedge |
rhynchospore blanc, white beak-rush, white beaksedge |
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Habit | Plants perennial, cespitose, 100–150 cm; rhizomes absent. | Plants perennial, densely cespitose, 6–75 cm; rhizomes mostly absent. |
Culms | erect to excurvedascending, narrowly linear to ± filiform, terete to obscurely trigonous, leafy, densely so toward base, stiff to rather lax. |
erect to curved, leafy, obscurely trigonous to nearly terete, few ribbed, slender. |
Leaves | overtopped by culm; blades linear, ascending, proximally flat, 1–4 mm wide, apex trigonous, subulate, tapering gradually. |
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Inflorescences | spikelet clusters 1–3(–4), proximal mostly widely spaced, dense, broadly turbinate to hemispheric, to 2 cm broad; leafy bracts subulate, exceeding proximal spikelets, slightly or not exceeding most distal clusters. |
clusters 1 or 2–3, then widely spaced, narrowly turbinate to hemispheric, 1.5–2.5 cm wide; subtending leafy bracts often exceeded by distal cluster. |
Spikelets | redbrown, narrowly ovoid, (3–)3.5–5 mm, apex acute; fertile scales ovate, 3–3.5(–4) mm, apex acute, mostly with cusp or mucro 0.5–1 mm. |
pale brown to nearly white, ellipsoid, 3.5–5.5 mm, apex acute; fertile scales elliptic, 3–3.5(–4) mm, apex acute or acuminate, midrib excurrent as mucro. |
Flowers | bristles 5–6, from rudimentary to reaching tubercle tip, or (rarely) beyond, antrorsely barbellate. |
perianth bristles 10–12, slightly overtopping tubercle, retrorsely barbellate or rarely smooth, base often setose. |
Fruits | 1–3 per spikelet, (1.5–)2–2.2(–2.5) mm; body dark brown with pale center, lenticular, broadly ellipsoid to ± orbicular, (1.3–)1.5–1.7(–1.9) × 1–1.5 mm, margins pale, narrow or narrowly rounded, flowing to tubercle; surfaces dull, minutely longitudinally striate; tubercle compressed, triangular to triangularsubulate, 0.5–0.7(–0.9) mm. |
1(–2) per spikelet, (2.3–)2.5–3 mm; body pale brown with paler center, stipitateobovoid, lenticular, 1.5–1.8(–2) × 0.9–1.2 mm; surfaces transversely striate, relatively smooth, rim narrow, flowing to tubercle base; tubercle narrowly triangularsubulate, 0.5–1.2 mm. |
Principal | leaves mostly overtopped by culm; blades narrowly linear to filiform, proximally flat, 0.5–1.5 mm, apex tapering, trigonous. |
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Rhynchospora fascicularis |
Rhynchospora alba |
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Phenology | Fruiting late spring–fall or all year (south). | Fruiting summer–fall. |
Habitat | Sands and peats of interdunal swales, depressions in savannas, open flatwoods, and seep-bog edges | Acid, sphagnous, boggy, open sites, poor fens, often on floating mats or peaty interstices of rocky shores |
Elevation | 0–100 m (0–300 ft) | 0–2000 m (0–6600 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; VA; Central America; Bermuda
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AK; CA; CT; DE; GA; ID; IL; IN; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; OR; PA; RI; SC; TN; VA; VT; WA; WI; WV; AB; BC; MB; NB; NF; NS; NT; ON; PE; QC; SK; Fla(?); West Indies (Puerto Rico); South America(?); Eurasia
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Discussion | In her revision, S. Gale (1944) treated var. distans as the more slender version of the species, one with a smaller inflorescence, more distinctly margined fruit body, and consistently elongate perianth bristles. All those character states appear to vary independently over the total range of the species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The smooth-bristled Rhynchospora alba forma laeviseta Gale mostly occurs with the typical antrorsely barbellate type in Pennsylvania, the Great Lakes, British Columbia, Newfoundland, and Nova Scotia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 239. | FNA vol. 23, p. 214. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Schoenus fascicularis, Dichromena distans, Phaeocephalum fasciculare, Phaeocephalum distans, R. distans, R. distans var. fascicularis, R. dommucensis, R. fascicularis var. distans, Schoenus distans | Schoenus albus, Dichromena alba, Phaeocephalum album, R. luguillensis, Triodon albus |
Name authority | (Michaux) Vahl: Enum. Pl. 2: 234. (1805) | (Linnaeus) Vahl: Enum. Pl. 2: 236. (1805) |
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