This study includes the entire genus Palaquium since in the 35 years after the publication of the work of H. J. Lam on the Sapotaceae much new material has come to our disposal to broaden the knowledge of the genus. The results of the study could not have been obtained without the assistance of the Directors of the following herbaria who put their material available on loan: Berkeley (U.S.A.), Berlin, Brisbane, Bogor, Florence, Cambridge (U. S. A.), Geneva, Kepong, Kew, Kuching, Lae, Leiden, London, Melbourne, Oxford, Paris, Sandakan, Stockholm, Sydney and Washington, to whom I express my most sincere thanks.