Centres of Endemism in the Espinhaco Range: identifying cradles and museums of Asclepiadoideae (Apocynaceae)

Although the high diversity of neotropical plants is often associated with rain forests, another important location is open vegetation at mountain tops. In the present study, we investigated the phytogeographic patterns of the Espinhaco Range, in eastern Brazil, a region characterized by campos rupestres and marked by high levels of plant richness and endemism. Based on the occurrence of Asclepiadoideae (Apocynaceae) in a grid of 0.5o x 0.5o cells, we conducted cluster analyses and parsimony analysis of endemicity (PAE). We also calculated indexes of diversity and endemism and examined the distribution of palaeo- and neo-endemics. According to our data, the topographic gap between the Espinhaco Range of Minas Gerais and Bahia seems to be an important constraint for the dispersion of endemics, and the floristic similarity between northern Minas Gerais and Bahia is a result of species with broad distribution. Based on the seven areas of endemism that emerged from PAE, we defined five principal centres of endemism in the Espinhaco Range, including the region comprising Serra do Cipo and the Diamantina Plateau, in Minas Gerais, as the major Asclepiadoideae cradle, and Chapada Diamantina, in Bahia, as an Asclepiadoideae museum.