United States lichenologist from Indianapolis, Indiana, who trained at the University of Cincinnati. He went to France to study for a higher degree at the Université de Paris and worked at the Laboratoire de Cryptogamie on a Fulbright Scholarship. He returned to the United States and gained a PhD at the University of Wisconsin (1954). As a National Science Foundation Postdoctoral Fellow, he worked for a year at the Farlow Reference Library and Herbarium of Harvard University with I.M. Mackenzie. In 1955 he was appointed initially as an instructor in Botany at Duke University and later became the Hugo L. Blomquist Professor in Botany. He was elected president of the American Bryological and Lichenological Society of America (1987-1989) and of the Botanical Society of America (1991-1992).