Biogeography is the study of plant and animal distributions and the processes that produce these patterns. The Caribbean region includes the islands of the Greater Antilles (Cuba, Hispaniola, Jamaica & Puerto Rico), the Lesser Antilles (the smaller islands from San Marteen to St. Lucia), and surrounding continental regions of North, Central and South America. My studies of Caribbean Biogeography seek to discover and document the various paths taken by the plants of the Caribbean as their ancestors migrated and separated during their evolutionary journey. Comparing the distributions of related species with their evolutionary tree can reveal where a group originated, where it ended up, and how it got there. In the genus Exostema there appear to have been several migrations to the Antilles, including one via the uplands of South and Central America, and one via the lowland forests of Amazonia and the Lesser Antilles. I've organized (with Peter Fritsch) a symposium on "Phylogeny and Biogeography of Caribbean Plants" for the 2001 annual meeting of the Botanical Society of America and the American Society of Plant Taxonomists.