William Hiesey (1903–1998)

William McKinley Hiesey (August 21, 1903 – August 7, 1998) was an American botanist who specialized in ecological physiology. He was notable for his collaboration with Jens Clausen and David D. Keck at Stanford University in the 1930s. In 1949, the three of them were co-recipients of the Mary Soper Pope Memorial Award in botany.
He joined the Carnegie Institution's laboratory at Stanford University in 1926, where he worked with Jens Clausen and David Keck on a comprehensive comparative study of California flora from contrasting environments. As the plant physiologist of this group, Hiesey performed extensive research at field stations investigating the ecological differences of various plant races, resulting in the group's classic six-volume work, Experimental Studies on the Nature of Species (1940–58). He joined the department of plant biology at Stanford University in 1951.

He was the father of Elaine Pagels, Harrington Spear Paine Professor of Religion at Princeton University and a scholar of Early Christianity.

His last book, Interspecific Hybrid Derivatives Between Facultatively Apomictic Species of Bluegrasses & Their Responses to Contrasting Environments, was published in 1982.