Research Interests:

Our research spans a wide range of topics in plant systematics and evolution, involving undergraduate and graduate students as well as international collaborations. Our general research goal is to test systematic and evolutionary hypotheses in a phylogenetic context. We integrate information from DNA sequences, morphology, and fossils to reconstruct the phylogeny of plants and use the phylogeny as a basis to elucidate the biogeographic history (e.g., time and place of origin, time and routes of migration) and to understand the rate and pattern of molecular and morphological evolution. We apply molecular population genetics and phylogeographic approaches to study evolutionary patterns and dynamics in rare and endangered species, in natural hybrid zones, and polyploidy species. We have also expanded our research to evolutionary developmental genetics to understand the molecular and developmental basis of morphological changes. The dogwoods and their close relatives (Cornales) have been our main focus. Other plants we have studied or are currently studying include the buckeye genus, Aesculus, and the federally endangered smooth coneflower, Echinacea laevigata, and many others that display discontinuous distributions in eastern Asia and eastern North America.

Selected Publications