Plant taxonomy with emphasis on monographic and cytotaxonomic work in the Asteraceae, some general floristics. Presently working on systematics of Chrysot hamnus and related genera, taxonomy of Cannabis (marihuana), and a checklist of the native plants of the Florida panhandle. Flora of Franklin County, Florida, and phytogeography of the Apalachicola barrier islands. Study of rare and endangered plants of Florida panhandle. Plant anatomy with emphasis on compa rative studies in the Asteraceae,Cannabaceae, Sapotaceae; also ecological adaptation as expressed in plant structure.