Revision of the genus Prismatomeris Thw. (Rubia- ceae, Morindeae). 1987. (Opera Botanica, 94). 36 figs. (line-drawings). 62 p. Lex8vo. Paper bd.

The Southeast-Asiatic genus Prismatomeris Thw. (Rubiaceae, Morindeae)is revised. It consists of shrubs and small trees with white flowers inumbel-like cymes. Fifteen species are recognized. Two new species from Borneo, P. kinabaluensis J.T. Johansson and P. robusta J.T. Johansson,are described. Three new combinations, P. beccariana (Baillon) J.T.Johansson, P. fragrans Geddes subsp. andamanica (Ridl.) J.T. Johansson and P. tetrandra (Roxb.) K.Schum. subsp. malayana (Ridl.) J.T. Johansson are made. The genus Zeuxanthe Ridl. is included in Prismatomeris.Micromorphological features of the leaf epidermis and of the indumentum and the pollen grains have been investigated. Several types of colleters occur: in addition to the normal type, common in Rubiaceae, sessilespherical to cushion-shaped and stalked colleters have been found. The hairs are papilla-shaped or 1- to 4-celled. The pollen grains have areticulate sexine and are similar to those in Rennellia (Rubiaceae,Morindeae). It is suggested that the inflorescence type is derived from a compound dichasium. In many species fusion of inflorescence components and ovaries occurs. Diheterostyly is present in almost all species. The majority of the species is divided into three phytogeographical groups. The southern and eastern limits of the range of Prismatomeris coincide with the limits of the Sunda-shelf, includingthe Philippines, and with Wallace's line. The circumscription and taxonomic affinities of Prismatomeris are outlined. A key to the speciesis given.