Florae Malesianae Preacursores LI. Apocynaceae. I. 1. Carissa, 2. Catharanthus, 3. Melodinus, 4. Leuconotis, 5. Chilocarpus

Of the 5 genera mentioned in the title a revision is given of the species of the Malesian region. Critical notes are made on delimitation, subdivision, and/or distribution of Carissa, Melodinus, and Chilocarpus; Neokeithia is reduced to Chilocarpus which genus exhibits an unusual array of variation in fruit structure. Keys to the Malesian species are presented of Melodinus, Leuconotis, and Chilocarpus. The keys are followed by an enumeration of these species; each species is provided with a brief synonymy and an account of its distribution and ecology. Essential extensions of previous knowledge of distribution are documented briefly by citing select collections. Various reductions of species are made. In Melodinus 2 new species are described, in Leuconotis 1 new variety; in Chilocarpus 6 new species, I new variety, and 2 new combinations are proposed. An account of all specimens examined will appear in a separate Identification List