| Citation | Distinguished for his contributions to botanical exploration and plant systematics, especially of the flora of Amazonia. He is the author of important floras of parts of South America and systematic monographs of plant families, of the neotropics. In addition he has made major contributions to ethnobotany, the history of exploration in the tropics, tropical biogeography and the effects of climatic change on tropical floras. In his earlier position as Assistant Director of the New York Botanic Garden and now as Director of the Royal Botanic Gardens, Kew, he has identified and developed the international role of botanic gardens in nature conservation and in the protection of natural biodiversity |