William Ralph Maxon, botanist, was born in Oneida, New York, on February 27, 1877, where he received an early interest in the natural sciences from his father, a newspaper editor, who would take him on long walks through the countryside on Sundays when he was a small boy. Maxon entered Syracuse University in 1894 and received a Ph.B. in 1898. While at Syracuse he developed an interest in ferns, and in the summer of 1898 Maxon left for Columbia University to do postgraduate study on ferns under Lucien Marcus Underwood.
In November 1899, Maxon received an appointment as an aid in the United States National Museum, Division of Plants. Working his way up the professional ladder, Maxon became assistant curator in 1905, associate curator in 1914, and the second curator of that Division (Frederick Vernon Coville held the title of honorary curator, without remuneration, 1894-1937) from February 1, 1937, until May 31, 1946. Retiring in 1946, Maxon became an associate in botany, a position he held until his death on February 25, 1948.
Maxon specialized in the taxonomic study of Pteridophyta, especially those of tropical America, and was considered to be one of the leading systematic pteridologists of his time. He built up the fern collection in the United States National Herbarium from one of relative insignificance to one of the finest in quantity and quality in the western hemisphere. Between 1903 and 1926 he undertook nine major expeditions to tropical America. A heart attack in 1931 put a stop to any further explorations. In 1928, and again in 1930, Maxon worked overseas in European herbaria, including those in London, Copenhagen, and Berlin. Among his scientific papers, one of his most important series of writings was his "Studies of Tropical American Ferns," which was published in Contributions from the United States National Herbarium.
Maxon belonged to numerous scientific societies and was a fellow of the American Association for the Advancement Science and the American Academy of Arts and Sciences. He was an original member and president of the Biologists' Field Club of Washington, and he was president of the American Fern Society, 1898-1899, 1919-1933, and editor and editor-in-chief of its Journal from 1933 until his death. Maxon was awarded an honorary doctor of science degree from Syracuse University in 1922.