Abstract
The taxonomic account of the genus Colura sect. Gamolepis in the Malesian region is presented based on fresh materials from field surveys and herbarium specimens. Five species are recognised including: C. cristata, C. meijeri, C. valida, C. verdoornii, and one new species, C. sigmoidea, described and illustrated. The new species is similar to C. cristata, but differs in having dioicous sexuality, ovate to lanceolate lobule sac ending with a small apical crest (consisting of 3–5 cells), small valve consisting of 30–40 cells and basal median cells of valve adnate with hinge cells forming a sigmoid curve in outline. A key to species, taxonomic descriptions and illustrations are provided; ecology and geographical distribution of the species are noted.