The first monograph of this group of plants in the last 68 years.

Each of the 182 species covered in this book complete with synonymy and a detailed description is given and its distribution, relationships and taxonomic history are discussed. Each species is provided with a map showing its known distribution and is illustrated with line drawings and a number of colour photographs.

More than 1,000 colour photographs, together with the line drawings make the species readily identifiable.

2 Volumnes. Volumne 1 330 pages. Volumne 2 300 pages. Both Hardcover with Dustjacket.