This book provides a comprehensive monograph of the family Humiraceae. It includes information on economic botany, conservation, phylogenetic relationships, taxonomic history, ecology, cytology, anatomy, and phytochemistry, among other topics. This volume is illustrated with line drawings, black and white photographs, and distribution maps. It was written by the world-leading authority on this plant group and contains a total of eight genera, 65 species, and 15 infraspecific taxa, with two new species described. This work is volume 123 in the Flora Neotropica 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.