When Bailey began studying palms, about 700 species had been identified. The number reached thousand by 1946, the rise due in large part to his intensive study of the family. Ill health finally forced Bailey to discontinue collecting abroad in 1949, at the age of 91. He continued to study, compare, and write about his palm specimens. His ultimate goal was to produce an authoritative guide to all palms, titled Genera Palmarum. When he died, he left behind a manuscript of the first page of the introduction. Genera Palmarum was ultimately published by Drs. Natalie Uhl and John Dransfield in 1987. A second, expanded, edition was released in 2008.
