XVI International Botanical Congess

The Proteaceae are an exemplary Gondwanic family: their distribution closely coincides with Gondwanic geological boundaries and fourteen well-supported clades show overlapping, trans-oceanic tracks. Several sources of evidence, each with its limitations, can help in inferring details of the family's biogeographic history. The Cretaceous fossil pollen record suggests that Proteaceae had diversified before Gondwanic fragmentation. However, palynological data have yet to be integrated with current phylogenetic knowledge. Cladistic biogeography promises to reconstruct the historical relationships between disjunct Gondwanic floras but resolving cladistic relationships within the relevant clades is proving to be more difficult than expected. Molecular phylogenies can also be used, in conjunction with the assumption of a molecular clock, to estimate the timing of key speciation events.