This volume was first published in 1997, providing the first comprehensive, botanically detailed and up-to-date survey of this beautiful group of plants since publication of The Genus Iris by W. R. Dykes. Following the pattern of the original Dykes monograph, botanical details, cultivation suggestions and general comments are supplied, and the work is generously illustrated with accurate line drawings, colour pictures of unusual species and distribution maps. This survey includes all of the species described so far and takes into account the many changes in classification which have taken place in the group. Information scattered in the literature is brought together in one volume to provide an authoritative reference for professional botanists and growers, and a mine of useful information for amateur gardeners and iris enthusiasts. A 2010 preface has been written especially for the re-issue of this important text.