Francis Raymond Fosberg (1908-1993) was born in Spokane, Washington, and grew up in Turlock, California, with an early interest in natural history. He received his B.A. in botany from Pomona College in 1930. After graduation, he took a position at the Los Angeles County Museum researching plants of the desert Southwest and islands off the coast of California. This research led to his interests in island ecosystems, and in 1932 he moved to Honolulu to accept a position as a research assistant at the University of Hawaii. While in Hawaii, he was invited to participate in the Mangareva Expedition. He received his M.S. in botany from the University of Hawaii in 1937 and his Ph.D. from the University of Pennsylvania in 1939. Fosberg accepted a position at the United States Department of Agriculture (USDA) and was sent to Colombia to identify stands of Cinchona for quinine production for the war effort. After World War II, he participated in a survey of economic resources in the Micronesian Islands. Upon his return to the United States, he and his new assistant, Marie-Hélène Sachet, began vegetation work for the newly formed Pacific Science Board under the National Research Council. Fosberg was also involved in the development of a joint program of the South Pacific Commission and the Pacific Science Board called the Coral Atoll Program, publishing papers twice a year.
Fosberg began his fifteen-year career at the United States Geological Survey (USGS) in 1951, mapping the military geology of islands in the Pacific. During his years there he also participated in many conferences, congresses, and scientific organizations such as the Pacific Science Association; United Nations Educational, Scientific, and Cultural Organization; the Pacific Science Board; and the American Association for the Advancement of Science. In 1966, Fosberg took a position at the Smithsonian's National Museum of Natural History (NMNH) in the tropical biology branch of the Ecology Program. Sachet was also appointed to the Program, allowing a continuation of their joint research. In 1968, with the demise of the Program, he and Sachet transferred to the Department of Botany, where Fosberg became Curator. He became Senior Botanist in 1976 and continued his career as Botanist Emeritus from 1978 to 1993.