New molecular phylogenetic evidence for Indian endemic species of the tribe Merremieae, Convolvulaceae

Abstract

Recent advances in molecular phylogenetics in the family Convolvulaceae Juss. (particularly in formerly recognized tribe Merremieae) have brought new insights on generic delimitation. Therefore, many species were transferred across genera to accommodate the new classification. However, additional morphological and molecular analyses are still needed to address the affinities and position of some species formerly included in Merremia Dennst. ex Endl.s.l. and allied genera. In this study, we provide a phylogenetic framework for the placement of Indian species in a new generic arrangement and to address the status of doubtful distinct species. Distimake rhyncorhiza (Dalzell) A.R. Simões & Staples is proved to have its place in Distimake Raf., while Operculina tansaensis Santapau & Patel is validated as a distinct species from O. turpethum (L.) Silva Manso. A nomenclatural clarification for the misuse of the name “Merremia gangetica (L.) Cufod”. in India is provided, with an encouragement to use the correct name Merremia emarginata (Burm.f.) Hallier f. The addition of the Indian species to the molecular phylogeny suggests the possible non-monophyly of Camonea Raf., and a new placement for Camonea vitifolia (Burm.f.) A.R. Simões & Staples, albeit still weakly supported. We have provided morphological descriptions, distribution maps and notes on nomenclature.