Pliocene intercontinental dispersal from Africa to Southeast Asia highlighted by the new species <i>Begonia afromigrata</i> (Begoniaceae)

Abstract

Abstract A new Begonia species from Laos and Thailand is described. It belongs to Begonia sect. Tetraphila , along with 30 other species which are all endemic to Africa. This is the first record of any of the 65 currently accepted sections in Begonia transgressing continental borders. A dated molecular phylogeny places the split of the new Asian species from its African congeners during the late Miocene to the early Pleistocene. As the species is a hygromesophilous epiphyte limited to tropical forest, no suitable corridor for migration existed during that time and the cause of the Afro–Asian disjunction probably is a long–distance dispersal event. The discovery of B. afromigrata emphasises the importance of chance in the assembly of tropical floras.