Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section Cyanococcus within the genus Vaccinium. Vaccinium also includes cranberries, bilberries, huckleberries and Madeira blueberries. Commercial blueberries—both wild (lowbush) and cultivated (highbush)—are all native to North America. The highbush varieties were introduced into Europe during the 1930s.
Blueberries are usually prostrate shrubs that can vary in size from to in height. In commercial production of blueberries, the species with small, pea-size berries growing on low-level bushes are known as "lowbush blueberries" (synonymous with "wild"), while the species with larger berries growing on taller, cultivated bushes are known as "highbush blueberries". Canada is the leading producer of lowbush blueberries, while the United States produces some 40% of the world supply of highbush blueberries.
The genus Vaccinium has a mostly circumpolar distribution, with species mainly present in North America, Europe, and Asia. Many commercially available species with English common names including "blueberry" are from North America, particularly Atlantic Canada and the northeastern United States for wild (lowbush) blueberries, and several US states and British Columbia for cultivated (highbush) blueberries. First Nations peoples of Canada consumed wild blueberries for millennia. Highbush blueberries were first cultivated in New Jersey around the beginning of the 20th century.
North American native species of blueberries are grown commercially in the Southern Hemisphere in Australia, New Zealand and South American nations. The Colombian or Andean blueberry, Vaccinium meridionale, is wild-harvested and commonly available locally. 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.