A contribution to the knowledge of the Melastomataceae occurring in the Malay Archipelago especially in the Netherlands East Indies

Originally it had been my intention to write a monograph of the Melastomataceae occurring in the Malay Archipelago. Owing to difficulties caused by the development of the political situation it was impossible for me, to carry out this plan to its full extent. As the important collections of the Herbarium of the Buitenzorg Botanical Garden could not be consulted and as most foreign herbaria too were inaccessible, I had to restrict myself almost entirely to the study of the collections preserved in the Utrecht and Leyden Herbaria. These however, though not so rich as those of the Buitenzorg herbarium, are very important, especially by the large number of type specimens. Of the great number of species described from parts of the Malay Archipelago outside the Dutch influence sphere, the types themselves could as a rule not be examined, and duplicates too were but rarely available. For this reason I was forced to restrict my endeavours almost entirely to the examination of the material collected in the parts known as the Netherlands East Indies. However, all genera known from the malayan region, for so far as they are in my opinion well-defined, have been incorporated in my keys. A detailed study of the Netherlands East Indian species was possible for me, as almost all important types are present in the Leyden and Utrecht Herbaria. The Melastomataceae especially those from Sumatra, Java and New Guinea are richly represented in these collections. Borneo, Celebes and the Lesser Sunda Islands probably would yield interesting results. The rich collections obtained from British North Borneo and Sarawak make it probable that the harvest obtained from the Netherlands part of Borneo will also contain many new and interesting forms, but of these collections but a small part has been distributed so far by the Buitenzorg herbarium