Phylogenetic biogeography of Euphrasia section Malesianae (Orobanchaceae) in Taiwan and Malesia

Species of Euphrasia are distributed in both hemispheres with a series of connecting localities on the mountain peaks of Taiwan and the Malesian region including Luzon, Borneo, Sulawesi, Seram and New Guinea. Two hypotheses are proposed to explain this distribution pattern. The Northern Hemisphere might have been the centre of origin or the Southern Hemisphere. This study aims to reconstruct the core phylogeny of Euphrasia in the connecting areas and tries to identify the migratory direction of Euphrasia in Taiwan and Malesia. The phylogeny of Euphrasia, including sections Euphrasia, Malesianae and Pauciflorae, is reconstructed with the chloroplast molecular markers rps2 gene, trnL intron and trnL-trnF intergenic spacer. The results suggest that the migratory direction between Taiwan and the Philippines is possibly from the north to the south. However, the migratory direction within section Malesianae and the centre of origin of Euphrasia remain unanswered from our data. More data is needed to clarify this issue.