XVI International Botanical Congess

Scaevola, the only genus in the Goodeniaceae with significant diversity outside of Australia, has dispersed throughout the Pacific Basin. The Pacific species are traditionally placed in Scaevola sect. Scaevola, which is characterized by fleshy fruits. We used ITS sequence data from Australian and Pacific species to test the monophyly of this section and to reconstruct its dispersal history. The genus Scaevola is a well supported monophyletic group, if the monotypic genus Diaspasis is included. Within the genus, two well supported clades emerged. One clade included all of the Southern Polynesian species, all but one New Caledonian species, and the widespread Pacific species, S. sericea. The second clade included the Hawaiian endemic diploids, the widespread Indian and Atlantic Ocean strand species, S. plumieri, and several australian taxa. The results imply that sect. Scaevola is paraphyletic, that fleshy fruits evolved at least twice, and that there were at least two major radiations into the Pacific Basin. This research is supported by the Lewis B. and Dorothy Cullman Foundation and the american Society of Plant Taxonomists.