American plant physiologist. William Austin Cannon was born in Washington, Michigan, and studied at Stanford and Columbia Universities, earning his PhD in 1901. As assistant to Daniel T. MacDougal, director of laboratories of the New York Botanical Gardens, he investigated the anatomy of plant hybrids and in 1902 became the first scientist to suggest the role of chromosomes in heredity. In 1903, he was selected by MacDougal and Frederick V. Colville, curator of the U.S. National Herbarium, to be the first resident investigator at the Carnegie Institution's Desert Laboratory in Tucson, Arizona, where he pioneered the study of the root systems and the physiological ecology of desert plants. Starting in 1907, he spent part of each year at the Coastal Laboratory in Carmel, California. Cannon resigned from the Carnegie Institution after a dispute with MacDougal in 1924 and took a position at Stanford University as a lecturer in botany, although he remained a research associate with the Carnegie Institution through 1934. After his retirement, he developed a classification scheme for root systems, which is still in use.

Cannon was interested in desert ecosystems in different parts of the world and made a series of comparative studies, but his larger goal of a comprehensive study of deserts never came to fruition. His research in the arid parts of Africa (Algeria 1910; South Africa and Namibia 1921), Australia (1918), and Mexico was published in occasional papers and in a series of books, Botanical Features of the Algerian Sahara (1913), Vegetation of the More Arid Portions of Southern Africa (1924), and Plant Habits and Habitats in the Arid Portions of South Australia (1921). He was one of the charter members of the Ecological Society of America in 1915.

Sources:
J.E. Bowers, 1990, “William A Cannon: The Sonoran Desert’s First Resident Ecologist”, Madrono, 37(1): 6-27.