Rhynchospora alba |
Rhynchospora macra |
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rhynchospore blanc, white beak-rush, white beaksedge |
large beaksedge |
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Habit | Plants perennial, densely cespitose, 6–75 cm; rhizomes mostly absent. | Plants perennial, cespitose, 40–80 cm; rhizomes absent. |
Culms | erect to curved, leafy, obscurely trigonous to nearly terete, few ribbed, slender. |
erect, trigonous, multiribbed, rather stiff. |
Inflorescences | 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. |
spikelet clusters 1–3, turbinate to hemispheric, 1.5–3 cm wide; subtending leafy bracts mostly exceeded by distal compound. |
Spikelets | 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. |
pale brown to nearly white, fusiform, 4–5(–7) mm, apex narrowly acute; fertile scales elliptic, 3.5–4 mm, apex narrowly acute, midrib excurrent as mucro. |
Flowers | perianth bristles 10–12, slightly overtopping tubercle, retrorsely barbellate or rarely smooth, base often setose. |
perianth bristles (15–)18–20, reaching tubercle tip, retrorsely barbellate. |
Fruits | 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. |
1 per spikelet, 2.5–3.2 mm; body brown with pale center, obovoid distal to short stipe, lenticular, 1.7–2.2 × 0.8–1.5, margins narrow, wirelike, flowing into tubercle edges; tubercle flat, narrowly triangular-subulate, 0.8–1 mm. |
Principal | leaves mostly overtopped by culm; blades narrowly linear to filiform, proximally flat, 0.5–1.5 mm, apex tapering, trigonous. |
leaves overtopped by culm; blades narrowly linear, proximally flat, (1.5–)2–3.5 mm wide, apex tapering, trigonous. |
Rhynchospora alba |
Rhynchospora macra |
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Phenology | Fruiting summer–fall. | Fruiting late summer–fall. |
Habitat | Acid, sphagnous, boggy, open sites, poor fens, often on floating mats or peaty interstices of rocky shores | Sands and sandy peats of savanna bogs and seeps, pinelands |
Elevation | 0–2000 m (0–6600 ft) | 0–200 m (0–700 ft) |
Distribution |
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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AL; FL; GA; LA; MS; NC; SC; TX; Central America (Nicaragua) |
Discussion | 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.) |
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Source | FNA vol. 23, p. 214. | FNA vol. 23, p. 214. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Schoenus albus, Dichromena alba, Phaeocephalum album, R. luguillensis, Triodon albus | R. alba var. macra, Phaeocephalum album var. macrum, Triodon albus var. macer |
Name authority | (Linnaeus) Vahl: Enum. Pl. 2: 236. (1805) | (C. B. Clarke ex Britton) Small: Man. S.E. Fl., 180. (1933) |
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