Plants forming small to extensive, open colonies, 0.8-10 dm; twigs green, glaucous, or yellow, ± angled, hairy in lines, often glabrous. Leaves deciduous; blade pale green or glaucous abaxially, dark green adaxially, ovate to broadly elliptic, 25-38 × 13-22 mm, membranous to subcoriaceous, margins ± entire, abaxial surface usually glabrous, rarely hairy, eglandular. Flowers: calyx green, glaucous, glabrous; corolla greenish white with pink striping, cylindro-urceolate, 4-10 mm; filaments ± glabrous. Berries usually blue, glaucous, 4-8 mm diam., glabrous. Seeds 5-20, ca. 1 mm. 2n = 24, 48. Flowering mid-late spring. Dry, open oak or oak- hickory woods, open pine woods, ledges, abandoned farmland or cut-over deciduous forests; 0-1600 m; Ont.; Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Kans., Ky., Maine, Md., Mass., Mich., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis. The flowers of Vaccinium pallidum are visited primarily by Andrena carlini Cockerell and Bombus spp. This species occasionally hybridizes with V. angustifolium, yielding V. ×dobbinii Burnham.
Colonial shrubs 2-8(-10) dm; bud-scales rounded above; lvs ovate to broadly elliptic, entire or seldom serrulate, the larger ones mostly (2.5-)3-5 cm, half as wide, glaucous beneath, sometimes also somewhat hairy; cal and pedicel glaucous; cor cylindric to urceolate, 4-8 mm; fr 5-8 mm, blue-glaucous or rarely black; 2n=24, or seldom 48. Dry upland woods and old fields; Me. to Minn., s. to Ga., Ala., Ark., and e. Okla. Apr.-June. (V. altomontanum; V. vacillans; Cyanococcus liparis; C. subcordatus; C. v.) Morphologically intermediate between nos. 11 [Vaccinium angustifolium Aiton] and 13 [Vaccinium myrtilloides Michx.], but apparently distinctive.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.