Cladistic analyses are performed on morphological and anatomical data of Fordia and Imbralyx. It is shown that both genera should be unified. Biogeographical analysis is performed and vicariance events are presented as results of speciation events due to climatic changes in the Pleistocene. The necessary new combinations for the species in Fordia and a key to all species have been presented in a separate paper (Dasuki & Schot, 1991, this issue).