Hernandiaceae comprise four genera and 50 species, some only known from their types. Seven species occur in Africa, four in Madagascar, 22 in the neotropics, 21 in Indochina, Malesia, and throughout the Pacific, and three in Australia; one species is pantropical. We have sequenced 23 species, and Old World and New World accessions of a pantropical species, for three cpDNA regions, amounting to 2265 aligned base pairs. As predicted by morphology, there is a deep split between an ancestrally African-Madagascan-Malesian lineage comprising Illigera and Hernandia and an African-neotropical lineage comprising Gyrocarpus and Sparattanthelium. The genera are monophyletic, and basal splits within three of them relate parsimoniously to the break-up of Gondwana. (Hernandiaceae have no confirmed fossils but their closest relatives, Monimiaceae and Lauraceae, were widespread by the Upper Cretaceous.) For Hernandia, with c. 20 species, Kubitzki (1969) proposed three dispersal events from Polynesia to Central America and subsequent dispersal from the West Indies to Sao Tome and Bioko (STB). Our data support minimally two arrivals in the neotropics, but minute sequence divergence within neotropical/Polynesian clades makes it difficult to resolve details; we have not yet sequenced the STB endemic, which has not been collected since 1972. African material of the pantropical Gyrocarpus americanus groups with the two African species of Gyrocarpus and not with neotropical G. americanus. Our results thus in essence support Kubitzki's scenario for the evolution of the family, although his wide concept of Gryocarpus americanus and subgroups of Hernandia need reinvestigation. Several species are endemic to islands of known geological age, providing possible minimal ages, and our poster will illustrate a time-explicit scenario for the spread of Hernandiaceae across the tropics.

Key words: Biogeography, Gondwana, long distance dispersal, molecular clock, pantropical species, phylogeography