Phylogeny reconstruction is central to my research. I use phylogeny reconstruction in evolutionary studies to identify how morphological diversity is patterned in monophyletic groups and to elucidate the forces that modify forms. I also use phylogeny reconstructions to resolve basic systematic problems, such as circumscription issues and evolutionary relationships. I maintain a strong interest in angiosperm macrosystematics, especially of the rosid and asterid clades. My recent research on angiosperm macrosystematics has focused largely on the Cornales and the transition to the more derived clades of Asteridae.
The fundamental questions about morphological diversity that I pose in my research include the following:
My research has focused on various groups of flowering plants, although I have had a long term interest in the systematics and diversification of the Cornales families Loasaceae and Hydrangeaceae. Other groups on which I have worked and maintain an interest include Saxifragales, Gyrostemonaceae, Sarraceniaceae and Scrophulariaceae (especially Besseya).