The centre of distribution of the Naucleeae is Malesia and Asia, there are but a few African and Madagascan representatives. The revision of the group for Flora Malesiana entailed an extensive nomenclatural evaluation and typification of the genera (Bakhuizen van den Brink Jr., 1970). This has been followed by detailed taxonomic investigations and a re-evaluation of the tribal and generic limits. The Naucleeae, as conceived by K. Schumann (1891), have mostly been considered a highly natural group (Verdcourt, 1958) and have even been raised to family status (Airy Shaw, 1973). Bremekamp (1966) has been the only botanist ever to question the homogeneous nature of the Naucleeae. However, after re-examination of materials of most representatives of all genera and sections of genera one could only come to a conclusion similar to Bremekamp’s. The only character that die genera of the tribe have in common is the arrangement of the inflorescence in a spherical head, a feature recurring independently in many tribes. The genera Mitragyna and Uncaria are here placed together in a subtribe Mitragyninae and transferred to the tribe Cinchoneae; Cephalanthus is transferred into a separate tribe, a move first suggested by Bremekamp (1966). These groups will be treated separately in papers shortly to appear. The remaining genera, as far as can be judged, form a somewhat homogeneous tribe.