Educated at the University of Iowa and Michigan Technological University he graduated BA 1969 and taught at Michigan Technological University and Michigan State University (1975-1983), and at the Missouri Botanical Garden, St. Louis, Missouri since 1983, where he has been Assistant Curator since April 2005 [REF].
He has conducted botanical expeditions in both Africa (Cameroons, Republic of Congo, Ethiopia, Kenya, Madagascar, Tanzania and Uganda) and the Americas (Costa Rica, Guatemala and Mexico).