[en] The Azorean flora, in contrast to that of other archipelagos, is characterized by a paucity of evolutionary radiations and the widespread distribution of most endemics. Several hypotheses, including isolation from the continent, recent age, ecological homogeneity, and limited paleoclimatic variations, have been proposed to account for this pattern. These hypotheses are tested here within the context of the molecular phylogeography of the heather Erica scoparia s.l., a Mediterraneo-Atlantic species complex distributed across Macaronesia, North Africa and southwestern Europe. The marked molecular radiation of this species in the Azores, including an array of single-island endemics, suggests that the apparent homogeneity of the Azorean flora might, in fact, conceal undetected patterns of endemism that are similar to those observed in the Canarian flora for morphological data. Haplotype richness was higher in the Azores than in the Canaries and extensive dispersal mediated allopatry is apparent at the molecular level. The Azores were colonized at least twice independently by E. scoparia, whereas the Canarian haplotypes are monophyletic, suggesting that the greater distance between the Azores and the continent does not necessarily hamper the chances of successful colonization.
