This work will be volume 124 in the Flora Neotropica Monograph book Series, Lawrence M. Kelly (Editor-in-Chief). Flora Neotropica volumes provide taxonomic treatments of plant groups or families growing in the Americas between the Tropic of Cancer and the Tropic of Capricorn. This monograph on Panicum (Poaceae), known as panicgrass, was written by the world-leading authority on this plant group. A total of one genus and 63 species are described. It also includes information on conservation, phylogenetic relationships, taxonomic history, ecology, cytology, and anatomy, among other topics. This is the first comprehensive volume on this topic since the 1920s and is lavishly illustrated with line drawings, black and white photographs, and distribution maps.