Members of the angiosperm family Begoniaceae are spread globally throughout the tropics and collectively comprise three genera: Begonia with approximately 1400 species, Symbegonia with 12 species endemic to New Guinea, and Hillebrandia which is monotypic and endemic to Hawaii. Begonia is currently divided among 63 sections with most sections being restricted to particular continents. Recent phylogenetic reconstructions have revealed distinct clades of American, Asian, and African species. Cladistic analyses using sequence data from ITS, rbcL and 18S indicate that African species of Begonia are basal and that Hillebrandia is the most ancestral member of the family. A broader phylogenetic analysis that includes representatives from the order Cucurbitales (Cucurbitaceae, Datiscaceae, Tetramelaceae, Begoniaceae, Coriariaceae, and Anisophylleaceae) provides an expanded view of Hillebrandia’s position within the order. The ancestral placement of Hillebrandia within Begoniaceae combined with its endemism to Hawaii poses an interesting biogeographic question.

Key words: Begoniaceae, Hillebrandia sandwichensis, phylogeny