This book is the most complete monograph ever published on this genus. All species are dealt with in detail, covering synonyms, etymology, a discussion chapter, description, distribution and habitat, flowering and miscellaneous items of interest.
85 species are detailed with their many varieties and forms. There are 25 line drawings, 112 pages of over 135 colour photographs, and 17 full page paintings by Linda W. Petchnick.
This work will become the standard for the genus for many years to come.
