Using flowering plants to address questions about plant biodiversity, biogeography, and evolution, I am interested in why some families of flowering plants are so species-rich and the factors that have promoted this diversification. Can certain families of plants be used as indicators of biodiversity hotspots and can this information be useful in conservation decisions? I am also studying species in a megadiverse family of plants like Princess Flowers (Melastomataceae) to determine how they are related to one another and where they fit into the tree of life for flowering plants.
For the past 30 years the major emphasis of my research has been the study of New World Acanthaceae (shrimp plants and their relatives). Although known in temperate regions primarily for showy ornamentals, the Acanthaceae are the 11th largest family of flowering plants (with more than 4,000 species) and a prominent element of many tropical regions. Mexico and Central America comprise a major center of diversity for this family.