Fleming, T.H. & Valiente-Banuet, A. (eds) (2002) Columnar cacti and their mutualists: evolution, ecology, and conservation. The University of Arizona Press, Tucson, AZ, U.S.A. xiii + 371 pp, figs, tables, line diagrams, halftones, index. Hardback: price US$65, ISBN 0-8165-2204-9.

I imagine that it is not that difficult to come up with an interesting book on columnar cacti and bats, as columnar cacti are the most interesting plants on earth and nectar-feeding bats the most interesting animals. Nevertheless, I would be curious to know whether the poor souls who have latched onto other topics of study (God forgive them!) would find this book as engaging as might cactus huggers. Part I on geology and evolution, for example, tends to be a bit dry, and there are no links among chapters that sometimes cover similar concepts in phylogeny. A detailed map is desperately needed to facilitate understanding and make the evolutionary history of Mexico and its cacti accessible to common mortals who do not specialize in this field.

The lack of flow throughout the book undoubtedly results from the fact that it is the outcome of a conference held in Mexico in 1998, and the planning for the book must have occurred a posteriori. That being said, we can only wish that all conferences gave birth to proceedings of such calibre. Part II on anatomy and physiology is very brief but raises the fascinating issue of cactus domestication by humans and its evolutionary consequences. Part III, entitled ‘Population and community ecology and conservation’, focuses on the ecology of the bat-cactus mutualism, and is the kind of dream stuff that leads people not involved in this field to severe depression and devastating regret. The title of the book does mention in a somewhat optimistic way ‘columnar cacti and their mutualists’, but bats as pollinators and dispersers are the only taxon covered in significant depth. Birds do make a brief appearance or two and the chapter on nurse plants for cacti is also noteworthy. Insects are mentioned in the book but other potential relationships are not. As for conservation, the book only discusses a couple of issues, and this section would have greatly benefited from a review of cactus status and conservation throughout the range of the taxon.

The greatest strength of the book resides in its richness of contributors (what a fabulous hall of fame) and is a testimony to the goodwill and exemplary collaboration that is taking place internationally in the bat-cactus scientific world. We may only regret the lack of certain Peruvian, Argentinean, and Caribbean contributors who could have helped with some missing pieces. The book emphasizes Mexican knowledge. It is a treasure of references, but I wish more contributors had referred to some very good North and South American theses. Theorizing on evolution involves a fair bit of speculation, and this book is no exception; any resource that can help unravel the fabulous story of columnar cacti is very valuable. It is not clear whether all chapters are reviews or not, but considering the lack of methods, I assume most are. The book claims to ‘summarize our current knowledge about the ecology, evolution, and conservation of columnar cacti and their vertebrate mutualists to show that the very survival of these cacti depends on animals who pollinate them and disperse their seeds.’ It does achieve the wonderful goal of summarizing the state of knowledge for columnar cactus ecology and evolution at the end of the 20th century, at least for North America (particularly Mexico) and northern South America, but its coverage of conservation is very frail. The most important accomplishment of this book is to have brought together many scientists who have a passion for columnar cacti. These plants and their mutualists represent life in many arid systems of the New World and their importance cannot be overemphasized. The contributors share with us many years of precious experience and their discoveries, among so much fascinating unknown, enhance the delightful mystery that has led us to become scientists. I’m going back for more! This book is a necessity for cactophiles, biogeographers of arid and semiarid zones in the New World, and anyone interested in general issues of pollination and seed dispersal in such areas.