Rhynchospora kunthii |
Rhynchospora alba |
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Kunth's beaksedge |
rhynchospore blanc, white beak-rush, white beaksedge |
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Habit | Plants solitary or in small tufts, (5–)10–70 cm, clonal; rhizomes strongly present, stoloniferous. | Plants perennial, densely cespitose, 6–75 cm; rhizomes mostly absent. |
Culms | leafiest toward base, ± trigonous, slender. |
erect to curved, leafy, obscurely trigonous to nearly terete, few ribbed, slender. |
Leaves | basal leaves spreadingascending, distal more erect, mostly exceeded by culms (except in highaltitude forms); blades proximally flat or strongly folded, 1.5–4 mm wide, apex trigonous, subulate. |
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Inflorescences | spikelet clusters (2–)3–5, compact, proximalmost widely spaced, turbinate to ovoid; peduncles ascending; branches ascending to spreading; leaf bracts exceeding proximalmost clusters, exceeded by distal cluster. |
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 | deep redbrown to nearly black, ovoid, 3–4 mm, apex acute; fertile scales ovate, 2.5–3 mm, apex acute, midrib included or shortexcurrent. |
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 | perianth bristles 6, some short, some extending to or nearly to tubercle base, antrorsely barbellate. |
perianth bristles 10–12, slightly overtopping tubercle, retrorsely barbellate or rarely smooth, base often setose. |
Fruits | 2–3 per spikelet, 2–2.1 mm; body pale yellowbrown, lenticular, broadly ellipsoidobovoid, 1.3–1.6 × 1–1.2 mm; surfaces transversely irregularly rugulose, intervals with rows of vertical, narrowly rectangular alveolae; tubercle evenly or concavely triangular, 0.5–0.6(–0.7) 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 kunthii |
Rhynchospora alba |
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Phenology | Fruiting late spring–summer. | Fruiting summer–fall. |
Habitat | Marsh meadows, seeps, boggy sites | Acid, sphagnous, boggy, open sites, poor fens, often on floating mats or peaty interstices of rocky shores |
Elevation | 1000–3500 m (3300–11500 ft) | 0–2000 m (0–6600 ft) |
Distribution |
CA; Mexico; South America (Colombia) |
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 | 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. 225. | FNA vol. 23, p. 214. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | R. schaffneri | Schoenus albus, Dichromena alba, Phaeocephalum album, R. luguillensis, Triodon albus |
Name authority | Nees ex Kunth: Enum. Pl. 2: 296. (1837) | (Linnaeus) Vahl: Enum. Pl. 2: 236. (1805) |
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