The tropical members of Ericaceae comprise most of the diversity within the family, with over 40 genera and over 1000 species described. This diversity is concentrated in tropical South America and in the large Pacific islands of New Guinea and Borneo, as well as the tropical Asian mainland. Previous workers have suggested a Gondwanan origin for the Ericaceae based on this diversity and Croizat considered Madagascar the center of distribution for Ericaceae based, in part, on the presence of Vaccinium in the mountains of East Africa and in Madagascar. Molecular systematic studies of the blueberry tribe (Vaccinieae) have shown that Vaccinium is polyphyletic and that tropical Vaccinieae have likely evolved from several temperate ancestors. Of the five major groups identified by the parsimony analysis of nrITS and matK sequences, two clades of tropical Pacific taxa have been identified. One of these (Agapetes clade) is closely related to the temperate Asian species of Vaccinium. The Dimorphanthera clade contains species that are also tropical Pacific in distribution, but this clade is not closely related to the Agapetes clade. Most of the species of tropical blueberries that occur in northern South America form a clade comprised of two groups: the Andean clade and a clade containing primarily Caribbean and Central American taxa. However, these clades do not include all of the members of the neotropical Vaccinieae. As in the tropical Pacific and Asian clades, the neotropical Vaccinieae have likely evolved from temperate ancestors. Results of molecular systematic studies of the wintergreen group show a similar pattern of tropical clades likely originating from northern temperate ancestors. These phylogenetic studies indicate that the tropical diversity found in Vaccinieae and the wintergreen group is a result of recent diversification and increasingly point to a Laurasian origin for the Ericaceae.

Key words: Gaultheria, tropical diversity, Vaccinium