Systematics and Molecular Phylogenetic Analysis of Erect Species of Ceropegia Section Buprestis (Apocynaceae: Asclepiadoideae), with Two New Species from India

Erect species of Ceropegia section Buprestis are revised based on morphology, palynology and molecular study, and a key to all species presented. Two new species, C. karulensis and C. maharashtrensis are described. The status of the systematically ambiguous C. lawii is addressed. In the molecular analysis of erect species using ISSR markers, taxa belonging to section Buprestis were found to be distinct from species of section Indopegia used as outgroup. The phylogenetic analysis of 20 Indian species of Ceropegia representing different sections and their congeners using nuclear ribosomal internal transcribed spacer (ITS) and non-coding chloroplast DNA (cpDNA) sequences shows that the erect species of section Buprestis form a separate clade along with section Indopegia. This supports Huber's hypothesis (1957) that the section Buprestis must have evolved from section Indopegia.