J. Torrey. Portrait of John Torrey (1796-1873), American botanist who began a major description and classification of North American flora. In 1824 he published Flora of the Northern and Middle Sections of the United States, in 1838-43 A Flora of North America and in 1843 Flora of the State of New York. He used specimens collected by himself and monographs sent by explorers of the North American continent to build up a collection of 40,000 species. He discarded the sexual classification of Linnaeus, introducing the 'natural' system of A. de Jussieu and A. de Candolle to America.