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rhynchospore blanc, white beak-rush, white beaksedge

spreading beaksedge

Habit Plants perennial, densely cespitose, 6–75 cm; rhizomes mostly absent. Plants perennial, densely cespitose, 10–60 cm; rhizomes absent.
Culms

erect to curved, leafy, obscurely trigonous to nearly terete, few ribbed, slender.

erect or spreadingarching, linearfiliform, terete, leafy toward base.

Leaves

overtopped by culm;

blades ascending, filiform, 0.3–0.5 mm wide, margins deeply involute, then channeled, apex trigonous, setaceous.

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 1–2(–4), dense(–open), narrowly to broadly turbinate;

branches capillary, variously elongate; leafy bracts setaceous, proximal exceeding clusters.

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.

brownish, lanceellipsoid to fusiform, 2–2.5(–3) mm, apex acute;

fertile scales broadly elliptic, 1.5 mm, apex narrowly rounded to broadly acute, apiculate, convexcupulate, midrib narrow, shortexcurrent or included.

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.

1–3 or more per spikelet, (0.6–)0.7–0.9(–1) mm;

body pale, glassy, obovoidlenticular, 0.6–0.7 × 0.4–0.5 mm, margins narrow, wirelike;

surfaces finely striate, very finely reticulate;

tubercle button depressedtriangular or patelliform, 0.1–0.15 mm, apiculate.

Principal

leaves mostly overtopped by culm;

blades narrowly linear to filiform, proximally flat, 0.5–1.5 mm, apex tapering, trigonous.

Rhynchospora alba

Rhynchospora divergens

Phenology Fruiting summer–fall. Fruiting summer–fall or all year (south).
Habitat Acid, sphagnous, boggy, open sites, poor fens, often on floating mats or peaty interstices of rocky shores Moist sands, peats, silts or clays of low meadows, bogs, flatwoods, sometimes seeps over calcareous rock
Elevation 0–2000 m (0–6600 ft) 0–300 m (0–1000 ft)
Distribution
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; LA; MS; NC; SC; TX; Central America; West Indies (Bahamas, Cuba, Dominican Republic)
[BONAP county map]
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.)

Source FNA vol. 23, p. 214. FNA vol. 23, p. 220.
Parent taxa Cyperaceae > Rhynchospora Cyperaceae > Rhynchospora
Sibling taxa
R. baldwinii, R. brachychaeta, R. breviseta, R. caduca, R. californica, R. capillacea, R. capitellata, R. careyana, R. cephalantha, R. chalarocephala, R. chapmanii, R. ciliaris, R. colorata, R. compressa, R. corniculata, R. crinipes, R. curtissii, R. debilis, R. decurrens, R. divergens, R. elliottii, R. eximia, R. fascicularis, R. fernaldii, R. filifolia, R. floridensis, R. fusca, R. globularis, R. glomerata, R. gracilenta, R. grayi, R. harperi, R. harveyi, R. indianolensis, R. inexpansa, R. inundata, R. knieskernii, R. kunthii, R. latifolia, R. macra, R. macrostachya, R. megalocarpa, R. megaplumosa, R. microcarpa, R. microcephala, R. miliacea, R. mixta, R. nitens, R. nivea, R. odorata, R. oligantha, R. pallida, R. perplexa, R. pineticola, R. pleiantha, R. plumosa, R. punctata, R. pusilla, R. rariflora, R. recognita, R. scirpoides, R. solitaria, R. stenophylla, R. thornei, R. torreyana, R. tracyi, R. wrightiana
R. alba, R. baldwinii, R. brachychaeta, R. breviseta, R. caduca, R. californica, R. capillacea, R. capitellata, R. careyana, R. cephalantha, R. chalarocephala, R. chapmanii, R. ciliaris, R. colorata, R. compressa, R. corniculata, R. crinipes, R. curtissii, R. debilis, R. decurrens, R. elliottii, R. eximia, R. fascicularis, R. fernaldii, R. filifolia, R. floridensis, R. fusca, R. globularis, R. glomerata, R. gracilenta, R. grayi, R. harperi, R. harveyi, R. indianolensis, R. inexpansa, R. inundata, R. knieskernii, R. kunthii, R. latifolia, R. macra, R. macrostachya, R. megalocarpa, R. megaplumosa, R. microcarpa, R. microcephala, R. miliacea, R. mixta, R. nitens, R. nivea, R. odorata, R. oligantha, R. pallida, R. perplexa, R. pineticola, R. pleiantha, R. plumosa, R. punctata, R. pusilla, R. rariflora, R. recognita, R. scirpoides, R. solitaria, R. stenophylla, R. thornei, R. torreyana, R. tracyi, R. wrightiana
Synonyms Schoenus albus, Dichromena alba, Phaeocephalum album, R. luguillensis, Triodon albus
Name authority (Linnaeus) Vahl: Enum. Pl. 2: 236. (1805) Chapman ex M. A. Curtis: Amer. J. Sci. Arts, ser. 2, 7: 409. (1849)
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