Distimake vitifolius (Convolvulaceae): reclassification of a widespread species in view of phylogenetics and convergent pollen evolution

Abstract

Distimake vitifolius comb. nov. (Convolvulaceae), currently treated as Camonea vitifolia, is a common and widespread species in South-East Asia. A recent study on the re-delimitation of the genus Merremia classified its species into six genera. The results of molecular phylogenetic analyses and the presence of hexazonocolpate pollen informed the transfer of Merremia vitifolia to Camonea. We present new molecular, morphological and palynological data and reinterpret previous results, demonstrating that the species should be classified in Distimake instead, reflecting the phylogenetic relationships of the species. Thus, the occurrence of hexazonocolpate pollen in both Distimake and Camonea is found to be the result of the convergent evolution of this apertural pattern in ‘Merremieae’, with implications for pollen evolution studies in the family. We formally transfer Camonea vitifolia to Distimake and present this reclassification as an example of the relevance of reciprocal reinterpretation of different sources of evidence in systematic studies.