In the circumscription as accepted here, the family consists of four genera of which three occur in Malesia: Gyrocarpus has 1 Malesian species, Hernandia 3, Illigera 9. The general family part of 5 pages includes a paragraph on vegetative anatomy by P. Baas, a paragraph on palynology by R.W.J.M. van der Ham, and a paragraph on phytochemistry by R. Hegnauer. The family, genera, and species are described and annotated; there are keys to the genera and species. Illustration is by three full-page line drawings and two photographs.