The first, only, and complete treatise on the cactus genus Coryphantha. The history of this North American cactus genus is presented in an understandable manner, along with the reclassification of all 43 species and 11 subspecies. A determination key allows for the easy identification of the diverse cacti within the genus. The species and subspecies are described in detail with both text and images. Useful tips for the care of each species round out the information provided. Contents include: Introduction to the genus, Ecology of Coryphantha, Morphology of Coryphantha, History of the genus, Position and delimitation of the genus, Determination key, Description of species, Cultural guidelines.