Reduction of Blinkworthia (Convolvulaceae) based on multilocus phylogenetic reconstruction and resurrection of a species from synonymy revealed by phenetic analyses

Abstract

Blinkworthia was established as a tropical Asian genus in the morning glory family (Convolvulaceae) with a unique combination of habit, bract, corolla and fruit morphology. Recently, however, investigations of the morphology and anatomy have shown that none of these diagnostic characters can be used to delimit Blinkworthia as an independent genus. This study resolves the generic circumscription using phylogenetic analysis of molecular data from four loci: ITS, trnL-trnF, matK and rps16. The results showed that all members of Blinkworthia were nested within Argyreia, concordant with the current morphological concept of Argyreia. All information robustly supported that Blinkworthia should be subsumed under Argyreia prompting us to make the nomenclatural transfers from Blinkworthia to Argyreia and make the new combinations A. convolvuloides and A. lycioides. In addition, phenetic analyses revealed that a species endemic to Burma, A. campanuliflora, should be resurrected from the synonymy of B. convolvuloides. The three species are circumscribed, described, illustrated and their ecology, distribution and vernacular names are summarised, all documented with specimen citations. An identification key is provided for these three closely related species.