The most comprehensive account yet published of this most popular genus of epiphytic cacti (also known under the name Zygocactus). The authors are internationally-known growers and breeders who have been studying the group over many years. Chapters on history, the species in the wild, hybridization and breeding, cultivation, propagation and pests and diseases, are followed by an encyclopaedic listing of historic varieties and modern cultivars (many here illustrated in colour), a bibliography and an index.