Book Description

"The Atlas of Illustrations, published as the second volume of The New Cactus Lexicon in 2006, set out to be the most comprehensive collection of images of these species yet published in book form, and remains a useful reference for those interested in the diversity of the cactus family or wishing to confirm or determine the identity of individual specimens. To satisfy continuing demand for copies, this edition is the response. It is basically a reprint with corrections of the original volume, but the pagesize has been reduced to economize on production costs and to achieve a substantial reduction in the cover price. The opportunity of a reprint also enables us to point out where recent research indicates or suggests improvements to the classification that can or could be made and to make minor rearrangements without upsetting the overall scheme (see the following pages). In the past two decades hypotheses concerning the phylogeny and evolution of the principal groups of cacti have been greatly encouraged and assisted by studies at the molecular level, enabling us to be more confident of relationships previously interpreted largely on the basis of morphological similarities and differences, and in a few cases to realise that we have been deceived by similarities that can now be attributed to evolutionary convergence. But whilst molecular evidence, summarized in the cladogram or phylogram that is now the sine qua non of a respectable taxonomic paper, may reliably indicate groups related or not related by common ancestry, it does not dictate the rank (genus or subgenus etc) at which the groups should be recognized--or tell us in practical terms how they are to be distinguished! So there is still plenty of scope for differing opinions, and general agreement or consensus on an updated list of genera to be recognized/not recognized seems a distant prospect. To date only a relatively small proportion of the family has received in depth analysis, and the results mostly await independent confirmation. The plants themselves, however, are unchanging, whatever we choose to call them, and the photographic record we have of them is factual and permanent, like preserved specimens in a scrapbook or herbarium (which some might regard as kind of a glorified scrapbook!) and sometimes, for cacti at least, more informative."--Preface.