In total, there are about 450 species, mostly in the cooler parts of the Northern Hemisphere. There are a few tropical species which grow in places like Madagascar or Hawaii. The plants usually grow in heathlands or in forests. Like most plants of the Ericaceae, many species grow in acidicsoils.
The taxonomy of the genus is complex, and is being investigated. Genetic analysis shows that the genus Vaccinium is not monophyletic.[1]Vaccinium's taxonomy can be fixed by enlarging the genus to include a number of related genera. Alternatively, the genus could be broken up into several different genera.[1]