Plants forming small to extensive clumps, rarely crown-forming, 2-30 dm, not rhizomatous; twigs of current season yellow-green or reddish green, terete to slightly angled, glabrous or hairy in lines. Leaf blades usually green, broadly elliptic to ovate, 25-50 × 11-23 mm, margins sharply serrate, surfaces glandular abaxially. Flowers: calyx green, obscurely lobed, glabrous; corolla white, cream, yellowish pink, or bronze, globose to urceolate, 3-5 × 5-7 mm, thin, glaucous; filaments glabrous. Berries shiny or dull black or deep purple, rarely red or white, 9-13 mm diam. Seeds ca. 1 mm. 2n = 48. Flowering late spring-early summer. Coniferous woods, especially cut-over stands, talus slopes, subalpine fir forests, alpine heaths; 900-3500 m; Alta., B.C., Ont.; Ariz., Calif., Colo., Idaho, Mich., Mont., Oreg., S.Dak., Utah, Wash., Wyo. Vaccinium membranaceum is, by far, the most widely commercially utilized western huckleberry for fruit and is harvested extensively from the wild. This species served as an especially important source of food for native peoples throughout western North America, and the dried berries were used for winter food and trade.
Branched, 5-10(-15) dm, usually ±colonial; lvs thin, deciduous, ovate-oblong to oblong, 3-6 cm, acute, finely aristate-serrulate throughout with incurved teeth, rounded at base, glabrous; petioles 2-3 mm; fls solitary in the lower axils of the season, nodding on pedicels 1-2 mm; sep very short and broad or nearly obsolete; cor subglobose, 5-6 mm; anthers spurred; fr purple or black, 8-10 mm. Moist woods; Bruce Penins., Ont.; Upper Penins., Mich.; Alta. and B.C. to n. Calif. and n. Utah; Ariz. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.