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.
From Flora of Indiana (1940) by Charles C. Deam
Erect, branching shrubs up to 4 feet high, usually 12-20 inches high. This species is restricted to the lake region and to the sandstone and knobstone area of the southern part of the state. Its preferred habitat is a dry sandy soil and it is rarely found in a moist soil unless it is that of a sandy black and pin oak woods in the lake region. In the southern part of the state it is generally associated with white, black, scarlet, and chestnut oaks, and Virginia pine. In [variety crinitum] the branchlets and under surface of the leaves are generally more or less permanently pubescent. It is much taller and the leaves are larger. I have it from Clark, Floyd, Jackson, Pulaski, St. Joseph, and Washington Counties. I do not know its general range.
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.