Florae Malesianae Praecursores LIX. Apocynaceae V. Ochrosia, Neisosperma

A revision with keys to and descriptions of the 5 Malesian species of Ochrosia Juss. (2 n. sp.) and 6 of Neisosperma Raf. Several species names are reduced. All types are mentioned. A selected number of specimens is cited; a full list of collectors will appear in the series Identification Lists of Malesian Specimens. Bleekeria Hassk. and Excavatia Markgr. are reduced to Ochrosia. In the note under Ochrosia there is a full discussion of the differences between this genus and Neisosperma, especially of the fruit for which some old types were microscopically examined. In Ochrosia the fruits are apocarpous, but in one species they are connate for one third, while in a new species from Flores they are united into a syncarpous, 2-celled drupe. In spite of the diversity of the fruit-structure in the two genera, they are very similar in flowers and vegetatively. For this reason, the key to the species in Ochrosia is preceded by a general (tentative) key to the species of both genera for practical purpose of identification of flowering material.