XVI International Botanical Congess

Most of the 150 species of Phylica are concentrated in Cape Province, South Africa, but five species are found on southern islands. According to phylogenetic analysis of plastid and nuclear DNA sequences the island species and a widespread South African species form a monophyletic group that is derived from within clades of the mainland species. This clade has undergone a phyletic radiation within these islands but has retained plesiomorphic morphologies due to occupation of mesic refugial habitats. In contrast the continental species have undergone extensive adaptive radiation in response to the increasingly dry climate and varied edaphic conditions in the Cape. The lack of morphological divergence among island species in Phylica may be contrasted with the great morphological divergence shown among species in other island groups.