Plants erect, not colonial, sometimes suckering, 10-50 dm; twigs green, angular to terete, usually hairy in lines. Leaves usually deciduous; blade dark green, ovate to narrowly elliptic, 15-70 × 10-25 mm, subcoriaceous, margins sharply serrate or entire, surfaces glabrous or hairy abaxially. Flowers: calyx green, glabrous; corolla white to pink, ± cylindric, 5-12 mm; filaments usually ciliate. Berries dull black to blue, glaucous, 4-12 mm diam., glabrous. Seeds 10-20(-25), ca. 1.2 mm. 2n = 24, 48, 72. Flowering spring(-early summer). Open swamps, bogs, sandy margins of lakes, ponds, and streams, flatwoods, gray-birch scrub, pine barrens, mires, bay heads, upland ericaceous meadows, upland woods, ravines, mountain summits; 0-1600 m; B.C., N.B., N.S., Ont., Que.; Ala., Conn., Del., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., Wash., W.Va., Wis.; introduced in Europe (Britain, The Netherlands), e Asia (Japan), Pacific Islands (New Zealand). Every morphological variant of the high-bush blueberry has been named formally at one time or another. At least 25 such taxa have been raised to specific rank; none is distinct throughout its putative range nor has the properties normally associated with biological species, including Vaccinium atrococcum and V. elliottii. See S. P. Vander Kloet (1980) for a complete list of synonyms. Feral populations readily become established wherever cultivars have been planted, e.g., Britain, British Columbia, Japan, Missouri, The Netherlands, New Zealand, Washington, and Wisconsin.
Crown-forming shrubs (0.5)1-3(-5) m; lvs ovate to narrowly elliptic, deciduous, 3-8 נ1.5-4 cm, variously serrulate or often entire, hairy (rarely glandular) or glabrous and sometimes glaucous; cor white or greenish-white to pink, cylindric to urceolate cylindric, 5-10 mm; fr blue-glaucous to black, 5-12 mm; 2n=24, 48, 72, ours mostly 48. Open swamps and bogs, or sometimes in upland woods or in old fields, from the coastal plain to the mt.-tops; Me. and N.S. to Fla., w. to Mich., n. Ill., Ky., Ark., e. Okla., and e. Tex. Apr.-July. (V. atrococcum; V. australe; V. caesariense; V. constablaei; V. marianum; V. simulatum; Cyanococcus atrococcus; C. margarettae; C. s.) Highly variable, not readily sorted into recognizable taxa. V. caesariense Mack., a diploid with glabrous, glaucous, entire lvs, glabrous or subglabrous twigs, and blue-glaucous fr, is ±distinguishable from the variable remainder of the group, diploid or often polyploid, with variously entire or serrulate, glabrous or hairy lvs and twigs, and blue or often black fr.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.