A TAXONOMIC REVISION OF THE MALESIAN GENUS TRIGONOPLEURA HOOK F (EUPHORBIACEAE)

Trigonopleura, a genus from W Malesia, has three species, the widespre ad T. malayana (Malay Peninsula, Sumatra, Borneo, Sulawesi) and the tw o endemic species T. dubia (Philippines) and T. macrocarpa (Sarawak, K uching). The species differ slightly from each other in leaf size, col our, and margin, flower and fruit size, fruit wall thickness, and aril size. A phylogenetic analysis was not performed, but it is argued tha t both endemic species split off separately from T. malayana. Trigonop leura is probably related to Chaetocarpus, in particular to C. castano carpus. Probably, Chaetocarpus is a paraphyletic group of species and will be monophylitic when united with Trigonopleura, but this will nee d thorough phylogenetic research. Here, both genera are kept separate, because they are very distinct (see Table 1). Typical for Trigonopleu ra are the fruits (wrinkled when dry, tomentose), the seeds (arillate) , the inflorescences (axillary clusters of flowers), and the flowers ( sepals imbricate, petals present, valvate, disc lobed, an androphore, 3 locules with one ovule each).