Species of Aglaia form an important component of most tropical forests in the Indo-Malesian region. Aglaia, with at least 105 species, is the largest genus in the family Meliaceae and has presented more taxonomic problems than any other genus in this family, especially in species delimitation. Variation is reticulate, involving different combinations of relatively few herbarium characters, each one of which may be variable and is rarely diagnostic on its own. This monograph is based on the examination of more than 10,000 herbarium collections, and on information gathered during four field trips to Western Malesia in which the author made comprehensive collections. 12 new species are described.
