James E. Eckenwalder is associate professor of plant systematics at the Department of Ecology and Evolutionary Biology at the University of Toronto, where he focuses on taxonomy, natural hybridization, and macroevolution. He graduated from Reed College in Portland, Oregon, and earned his doctorate from the University of California, Berkeley. His research, which has resulted in significant changes to conifer taxonomy, emphasizes the classification and evolution of vascular plants, especially trees. His interests include the theoretical and practical bases of plant classification, the tracing of...