Phylogeny and Biogeography of Erica

Abstract

The genus Erica (Ericeae, Ericoideae, Ericaceae) occurs in Europe, the Middle East, and Africa. Southern Africa has the largest number of species, especially at the southern tip of the continent. This narrow north-south distribution is unique in the Ericaeae and has fueled speculation about the origin of Erica species. Phylogenetic relationships among selected species of Erica were investigated in order to determine whether the origin of this genus lies in Europe or Africa. Three regions of DNA, one from the nuclear genome (nrITS) and two from the chloroplast (rbcL-atpâ spacer and matK), were selected as sources of molecular data for their previously demonstrated utility within the Ericaceae. Parsimony analysis of the African taxa indicates a monophyletic group derived from within the European taxa. Erica arborea has a broad range found in both Europe and Africa and appears as sister to the African clade, suggesting that the common ancestor of both E. arborea and the Cape African taxa was also widespread across both continents. This common ancestor appears to have expanded its range into Africa after the establishment of the connection between Europe and Africa during the mid-Miocene.