Abstract
Summary Chionanthus is the largest genus of Oleaceae in New Guinea and, of its 17 species on the island, eight are new species described and illustrated here. Its high level of endemism, 70% (12 species), is typical of the New Guinea flora. Most of these new species are restricted to Papua New Guinea but this is likely to be an artefact of lower collecting intensity in Indonesian New Guinea. However, the 17 species do not reflect the biodiversity of New Guinea Chionanthus, as there are already a further 15 – 20, unnamed, putative species in herbarium collections that are too incomplete to enable their formal description.