BOOK REVIEW
Ralph Shumm, Forest Grove, OR
NOTES FROM THE ROYAL BOTANIC GARDEN, EDINBURGH, Volume 39 No. 1
"Revision of Rhododendron Subgenus Rhododendron sections Rhododendron & Pogonanthum"
Dr. James Cullen
After several preliminary papers, a preliminary synopsis, and participation in the 1978 International Rhododendron Conference in New York, we have Dr. Cullen's completed revision of Rhododendron 1. Subgenus Rhododendron sections Rhododendron & Pogonanthum in "Notes from the Royal Botanic Garden, Edinburgh, Volume 39, No. 1, 1980."
The revision opens with 4 sections: General Introduction; Introduction to subgenus Rhododendron; Presentation of the revision; and Taxonomic characters. These first 22 pages are most valuable and informative reading for anyone with a serious interest in rhododendrons. Especially interesting are discussion and illustrations on scales (this volume covers only the scaly-leaved species), and on the geographic distribution of these species. There follows the detailed taxonomic account of each species. Section Rhododendron is divided into 27 sub-sections containing 149 species and Section Pogonanthum contains 13 species for a total of 162 species. (It should be noted that Dr. Cullen is sometimes referred to as a "lumper", eliminating a number of species as not being sufficiently distinct to warrant separate species status.) These taxonomic accounts are accompanied by numerous maps showing the geographic distribution of the species, a fascinating and helpful feature of the volume.
Another part of the book is a list of all the herbarium specimens studied. They are listed by the collector and the collector's number. (It is interesting to see what a tremendous contribution collector George Forrest made to the genus. Far beyond any other collector in number of species and volume of plant material.) The volume closes with outstanding sections on the interrelation of the subsections and on the geographical distribution. There is the usual, and in this volume most helpful, index to complete the work.
For the taxonomist, horticulturist, botanist, researcher, professional nurseryman and amateur hobbyist this is an important reference. For the casual rhododendron lover this volume could induce a more serious attention to the hobby. This revision has been long awaited by many of us and will certainly-influence the future of our joy, rhododendrons.