Hans Edmund Gruen was born in Berlin, Germany, on 20 October 1925. He attended primary and middle schools in Germany and Switzerland; and during World War II (from 1942-1946) he attended high school in Montevideo, Uruguay. Gruen became a naturalised U.S. citizen in 1950 and attended university in the United States, receiving his B.Sc. from Brooklyn College in 1951 (majoring in Biology) and both his M.Sc. (1953) and Ph.D. (1957) from Harvard, specialising in plant physiology and mycology. He did postdoctoral work at the Biological Laboratories, Harvard from 1956-1959, and from 1959-1964 was a research fellow at Harvard=s Farlow Herbarium with the exception of seven months in 1963 (March - September) when he was a Lalor Foundation research fellow in the Biological Institute of the College of General Education, University of Tokyo. In 1964 Gruen accepted a teaching position in the Department of Biology of the University of Saskatchewan; by 1973 he had been made full professor. While on sabbatical leave he returned three times to the University of Tokyo as visiting research scholar, during the 1971-72 and 1978-79 academic years at the College of General Education, and in 1985-86 at the Institute of Microbiology, College of Agriculture. He also served as associate editor (1980-1983) and acting co-editor (Nov. 1982 - May 1983) of the Canadian Journal of Botany. On 1 July 1993 the University of Saskatchewan awarded Gruen the title of Professor Emeritus. Hans Gruen died in Saskatoon on 7 September 2000.