Abstract
A total of 18 species of Psychotria with a climbing and/or hemi-epiphytic habit are enumerated as native to Peninsular Malaysia and Singapore. This number includes one newly described species, Psychotria deltata, known from Johore and Singapore; and one taxon raised to species rank, Psychotria euosma (based on Psychotria sarmentosa var. montana). A new record for Psychotria serpens from Peninsular Malaysia is presented, and a number of collections are tentatively placed in Psychotria chartacea, a species from Peninsular Thailand. Four species are added to the list of native taxa for Singapore. Psychotria kunstleri is synonymised with Psychotria ridleyi and P. cantleyi is reduced to P. scortechinii. Lectotypes are designated for nearly all names applied to climbing Psychotria taxa for Peninsular Malaysia and Singapore including the Linnaean species P. serpens.