My research area is angiosperm systematics, and in particular I focus on the following topics: (1) Evolution of morphological characters and the use of developmental data in developing homology hypotheses. (2) Species definition and the interpretation of molecular and morphological patterns at the base of the systematic hierarchy and their biogeographic implications. (3) Development and understanding of new characters, both morphological and molecular, for systematic use. (4) Systematic theory. The taxonomic group in which I work most is Orchidaceae, but I have interests in and active research in Ericaceae and Sarraceniaceae, as well as in higher level relationships among the monocots, especially the Hypoxidaceae and related families. My work in the orchids ranges from studies within individual genera (e.g., Corallorhiza) to investigation of relationships across the family. I focus on relationships in the largest subfamily, Epidendroideae, because this is where much of the diversity in characters and ecological specialization is found. I use molecular, morphological, and developmental data to reconstruct and study systematic patterns and morphological character evolution. One question that my group is addressing is which characters are correlated with the radiations that we see in the orchids. I am also currently investigating the fungal association of orchids from a systematic perspective. Research in Ericaceae and Sarracenia focuses on phylogenetic reconstruction to study biogeographic patterns and to understand morphological evolution. Work on systematic theory includes studies of different types of character coding and phylogenetic methods, as well as consideration of the nature of systematics evidence and patterns.