Compsoneura is a Neotropical genus of trees distributed primarily in the lowland wet forests from Bolivia and southern Brazil north to Veracruz, Mexico. Herbarium, field, and laboratory studies were conducted between 1997-2000 with the ultimate goal of producing a monographic treatment for this genus. Herbarium studies included analysis of approximately 2,500 specimens, with rigorous sampling of label and morphological data from each specimen. Geographic coordinate data for every collection were generated for use in GIS-based mapping and geospatial analysis. Stereomicroscopy and Scanning Electron Microscopy (SEM) were applied in a morphological analysis for all species in Compsoneura. Multivariate procedures of quantitative analysis were applied in order to investigate morphological variation and implications for species delimitations. Microsatellite DNA markers were used to elucidate one difficult, widespread species complex, Compsoneura sprucei sensu lato. A qualitative data matrix of 40 characters was analyzed using parsimony methods to investigate in-group evolutionary and biogeographic patterns. Combinations of multivariate and parsimony analyses provided a better overall view of interspecific and subgeneric patterns, respectively. A total of 20 species are currently recognized, including seven species new to science and a new combination. The classification proposed by Warburg (1897) and accepted by Smith (1937) was revised, involving the description of a new generic section (Hadrocarpa). Previous emphasis of the Warburgian system on androecial characteristics was found to be insufficient in light of more comprehensive information from leaves, staminate and pistillate flowers, androecia, gynoecia, fruit, aril, and seeds. Furthermore, the new section Hadrocarpa may represent a new genus for the Neotropics. This taxonomic hypothesis awaits further testing with outgroups and inclusion of molecular data. Results, implications, and lessons from studies of Compsoneura will be presented, with demonstration of the importance of basic monographic work in the Neotropics and beyond.

Key words: Compsoneura, monographic research, Myristicaceae, Neotropical forest, Neotropics, taxonomy