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 blueberriesboth 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 10 centimeters (4 inches) to 4 meters (13 feet) 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. Origin and history of cultivation 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 before North America was colonized by Europeans.