This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Branching shrubs (some species small trees) with alternate often coriaceous leaves, and small white, pink or red flowers, in terminal or lateral racemes or clusters, or rarely solitary in the axils. Calyx-tube globose, hemispheric or turbinate, not angled, adnate to the ovary, the limb 5-toothed or 5-lobed, persistent. Corolla urn-shaped or cylindric, rarely subglobose, its limb 5-toothed or 5-lobed. Stamens twice as many as the lobes of the corolla, distinct, the filaments short or elongated; anthers awned or awnless, upwardly prolonged into tubes, opening by terminal pores or chinks. Ovary 5-celled, or 10-celled by false partitions; ovules several or numerous in each cavity; style straight; stigma small. Fruit a many-seeded berry. [Latin name for these or related plants.]
About 150 species of wide geographic distribution. Besides the following some 11 others occur in southern and western North America. Type species: Vaccinium Myrtillus L. Flowers solitary, or 2-4 together, on drooping pedicels; low shrubs; filaments glabrous; anthers 2-awned.
Most or all the flowers 4-parted and stamens 8.
Flowers all or nearly all 5-parted, and stamens 10.
Shrub 3'-6' high; leaves obovate or cuneate.
Shrubs 1°-12° high; leaves oval or oblong; northern species.
Flowers fascicled or racemose, short-pedicelled; filaments pubescent; anthers awnless.
Fruit normally blue, with a bloom.
Corolla subcampanulate, greenish-pink.
Corolla urceolate to subcylindric.
Corolla subcylindric, 3"-6' long.
Corolla urceolate, 2" - 3" long.
Low upland or mountain shrubs, mostly less than 40 high, leaves small; corolla white to greenish pink.
Leaves oblong, lanceolate or narrowly elliptic, green on both sides,
Leaves and twigs densely short-pubescent.
Leaves and twigs glabrous or nearly so.
Leaves obovate to broadly oblong, pale beneath.
Fruit normally black, with no bloom or very little.
Corolla globose-ovoid to urceolate.
Low shrub of rocky places; leaves glaucous beneath.
Tall shrubs; leaves green on both sides, somewhat paler beneath.
Leaves entire-margined, thin, densely pubescent beneath, 1 1/2' - 3' long; marsh shrub.
Leaves serrulate, firm, glabrous or nearly so, 1' long or less; pineland shrub.
Corolla nearly cylindric.
Tall swamp shrub; corolla pink, 3"-4" long.
Low upland shrub; corolla white, 2"-3" long.