Blueberries are flowering plants with indigo colored berries. They are classified in the section Cyanococcus within the genus Vaccinium. Vaccinium also includes cranberries, bilberries, and gooseberries. Commercial „blueberries“ are native to North America, and the „highbush“ varieties were not introduced into Europe until the 1930s.
The genus Vaccinium has a mostly circumpolar distribution, with species mainly being present in North America, Europe, and Asia.
Many commercially sold species with English common names including „blueberry“ are from North America. Many North American native species of blueberries are grown commercially in the Southern Hemisphere in Australia, New Zealand and South American nations.
Several other wild shrubs of the genus Vaccinium also produce commonly eaten blue berries, such as the predominantly European Vaccinium myrtillus and other bilberries, which in many languages have a name that translates to „blueberry“ in English. See the Identification section for more information.
Blueberries may be cultivated, or they may be picked from semiwild or wild bushes. In North America, the most common cultivated species is V. corymbosum, the northern highbush blueberry. Hybrids of this with other Vaccinium species adapted to southern U.S. climates are known collectively as southern highbush blueberries.
So-called „wild“ (lowbush) blueberries, smaller than cultivated highbush ones, have intense color. The lowbush blueberry, V. angustifolium, is found from the Atlantic provinces westward to Quebec and southward to Michigan and West Virginia. In some areas, it produces natural „blueberry barrens“, where it is the dominant species covering large areas. Several First Nations communities in Ontario are involved in harvesting wild blueberries.
„Wild“ has been adopted as a marketing term for harvests of managed native stands of lowbush blueberries. The bushes are not planted or genetically manipulated, but they are pruned or burned over every two years, and pests are „managed“.
Numerous highbush cultivars of blueberries are available, with diversity among them, each having individual qualities. A blueberry breeding program has been established by the USDA-ARS breeding program at Beltsville, Maryland, and Chatsworth, New Jersey. This program began when Frederick Vernon Coville of the USDA-ARS collaborated with Elizabeth Coleman White of New Jersey. In the early part of the 20th century, White offered pineland residents cash for wild blueberry plants with unusually large fruit. After 1910 Coville began to work on blueberry, and was the first to discover the importance of soil acidity (blueberries need highly acidic soil), that blueberries do not self-pollinate, and the effects of cold on blueberries and other plant. In 1911, he began a program of research in conjunction with White, daughter of the owner of the extensive cranberry bogs at Whitesbog in the New Jersey Pine Barrens. His work doubled the size of some strains‘ fruit, and by 1916, he had succeeded in cultivating blueberries, making them a valuable crop in the Northeastern United States. For this work he received the George Roberts White Medal of Honor from the Massachusetts Horticultural Society.
Blueberries consist of 14% carbohydrates, 0.7% protein, 0.3% fat and 84% water. They contain only negligible amounts of micronutrients, with moderate levels (relative to respective Daily Values) (DV) of the essential dietary mineral manganese, vitamin C, vitamin K and dietary fiber. Generally, nutrient contents of blueberries are a low percentage of the DV. One serving provides a relatively low caloric value of 57 kcal per 100 g serving and glycemic load score of 6 out of 100 per day.