The genus Psychotria (Rubiaceae) is probably the world’s largest predominately woody genus with perhaps around 2000 species. It has a pantropical distribution and is often a very obvious and species-rich component of humid, tropical forests, particularly in Africa, south-east Asia, and South America. The high number of species, coupled with bewildering systematic complexity, has resulted in a genus that is poorly known, particularly in south-east Asia.
The main part of the work consists of a classical taxonomic revision of the genus Psychotria in the Philippine Archipelago. The authors recognize 112 species, including 17 infraspecific taxa; 29 species and nine varieties are new to science; six new combinations are made and three new names (nomen novum) are proposed. Identification keys are provided for the nine informal species groups, species within each of these groups, and for the infraspecific taxa.
This work will serve as a major reference for Psychotria in the Philippines and south-east Asia, and will be welcomed by botanists, conservationists, natural history field workers, and Rubiaceae taxonomists.