The decision to write this dictionary was prompted by Cacti: The Illustrated Dictionary by Rod and Ken Preston-Mafham, which so successfully met a need among cactus enthusiasts. Succulents other than cacti are described and illustrated in several monographic studies dealing with a single genus or a specific geographical region, but there is no single book with a large number of colour illustrations covering a wide range of genera. It is hoped that this dictionary will go some way towards filling this gap, helping collectors to identify their plants and encouraging newcomers to select interesting species to study and grow.

We would like to emphasize that we do not pretend to have found a solution to the chaos afflicting the classification of succulent plants - rather, we are completely involved in that chaos. The classification of both succulents and cacti is affected by several factors that lead to frequent changes and to the creation of very small genera and new specics. The main problem is probably the horticultural value of new species. Nurserymen often offer unidentified specimens as sp. nova to stimulate the potential collector's interest. If a plant is described and published as a new species in accordance with the rules of the International Code of Botanical Nomenclature but without the plant's variability in habitat having been verified, a new species could be established, which, although valid in formal terms, has no biological meaning.

It is essential that a group of experts attempt to define a system that will bring some stability to the naming of succulent plants and will cut the plethora of generic and specific names that afflicts this group of plants. The International Organization for Succulent Plants Study (IOS) is aiming to complete a project that will find a consensus among cactus experts on the naming of the Cactaceae. It is to be hoped that the IOS will be able to carry out a similar project for succu-

In this dictionary we have used the names currently found in private and public collections. Including available revisions would have resulted in a partial work with no coherent criteria that would confuse the average collector. Some revisions are noted in the descriptions of the succulent species and for those readers who are interested in pursuing the subject further there are books listed in Further Reading.

0 0

Post a comment