Rhynchospora alba |
Rhynchospora curtissii |
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rhynchospore blanc, white beak-rush, white beaksedge |
Curtiss' beaksedge |
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Habit | Plants perennial, densely cespitose, 6–75 cm; rhizomes mostly absent. | Plants perennial, densely cespitose, 10–30 cm; rhizomes absent. |
Culms | erect to curved, leafy, obscurely trigonous to nearly terete, few ribbed, slender. |
lax, erect to excurved, leafy toward base, filiform. |
Leaves | overtopped by scape; blades filiform, distally flattened, channeled, tapering, to 1 mm wide, margins strongly involute, apex blunt. |
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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, laterals widely spaced, all narrowly turbinate, ellipsoid, or ovoid; leafy bracts setaceous, overtopping proximal clusters, often overtopped by terminal ones. |
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. |
erect or ascending, redbrown, lanciform, mostly 4.5–5 mm, apex acute; fertile scales lanceolate, (3–)4–4.5 mm, apex acute, apiculate. |
Flowers | perianth bristles 10–12, slightly overtopping tubercle, retrorsely barbellate or rarely smooth, base often setose. |
perianth absent. |
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. |
2–3(–5) per spikelet; stipe and receptacle 0.1–0.2(–0.3) mm, setose; body brown with pale glassy center, narrowly obovoidellipsoid, lenticular, 1.2–1.5 mm, margins narrow, flowing to tubercle; surfaces very finely lined longitudinally, transversely with wavy lines of tiny pits; tubercle narrowly triangular or slightly concavesided, flattened, 0.7–1.2(–1.5) 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 alba |
Rhynchospora curtissii |
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Phenology | Fruiting summer–fall. | Fruiting summer–fall. |
Habitat | Acid, sphagnous, boggy, open sites, poor fens, often on floating mats or peaty interstices of rocky shores | Sands and peats of bogs, pineland pond shores, seeps, and low moist savannas |
Elevation | 0–2000 m (0–6600 ft) | 0–100 m (0–300 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; MS |
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. 234. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Schoenus albus, Dichromena alba, Phaeocephalum album, R. luguillensis, Triodon albus | Phaeocephalum curtissii, R. filifolia var. ellipsoidea |
Name authority | (Linnaeus) Vahl: Enum. Pl. 2: 236. (1805) | Britton: in J. K. Small, Fl. S.E. U.S., 195, 1327. (1903) |
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