Both is the enchanting account of a remarkable fifty-year relationship: Dwight Ripley, the child heir to an American railroad fortune, and Rupert Barneby, the product of a wealthy, baronial English upbringing, shared an obsession with botany from the moment they met at an exclusive boys’ boarding school in England. Together they embarked on a lifelong pursuit of rare plants, first in Europe and then in the United States, where they migrated in the late 1930s.

Every spring they explored the American Southwest in a sputtering Dodge, discovering new species and cultivating the spoils at their renowned home gardens. Barneby published so many taxonomic findings that he became a world authority on legumes. But the two men had other interests as well: they were intimates in the expatriate circles that included W. H. Auden and Peggy Guggenheim, and early collectors of painters such as Jackson Pollock and Joan Miró. Ripley, a prescient artist himself, whose startling work in colored pencil was lost in a trunk for several decades before being rediscovered, used his fortune to bankroll much of the avant-garde art scene of the early 1950s.

The lives of Ripley and Barneby were shaped by a passion for knowing the world in all its lush particulars. Douglas Crase, who received an education in character when he came to know Barneby in the 1970s, offers us not just the brilliantly told story of “both,” but a vivid portrait of the bohemian postwar period they inhabited, bristling with the energy of the new.