This is a complete guide to the cactus flora of Colorado. It covers 24 species and varieties, including 2 new species, and includes range maps and taxonomic keys. The book contains over 270 pictures and diagrams and provides technical taxonomic species comparisons with text and photos. Introductory chapters cover diverse topics, such as the history of Colorado botanists, vegetation, an overview of ecological regions and life zones in Colorado, where to view cactuses in protected public lands, cultural uses and history of use of cactuses, biological controls including insects and fungal diseases, and cactus cultivars and where to buy these locally.