Hoya corymbosa (Apocynaceae, Asclepiadoideae), a New Unusual Species from Sabah, Borneo, and its Systematic Position based on Phylogenetic Analysis

Abstract—

A new species, Hoya corymbosa , from Sabah (Borneo), is described and illustrated. It is a horizontally growing epiphytic shrub with diminutive flowers. Its minute staminal corona lobes lacking revolute outer margins and broad, flat caudicles of the pollinarium (resembling those of Dischidia) are quite peculiar within the genus, which is otherwise characterized by corona lobes with revolute margins and generally round to oval caudicles. Its position in Hoya has been confirmed by phylogenetic analysis based on nuclear ribosomal ITS region, the matK gene and psbA-trnH intergenic spacer.