An Enthusiasm for Orchids: Sex and Deception in Plant Evolution

  • John Alcock
Oxford University Press: 2006. 320 pp. £17.99, $29.99 019518274X | ISBN: 0-195-18274-X

Botanists have devoted much time, energy and money to understanding the complexities of evolution, adaptation and speciation. In my view, orchids provide the best examples of evolutionary adaptations, because of their intricate relationships with their pollinators.

Anyone trying to learn about orchids could, however, easily be put off by the terminology and the bizarre floral characters unique to these plants. What's needed is a book that presents these complex floral characters in an understandable and attractive way. John Alcock's book An Enthusiasm for Orchids does this.

Designed to deceive: an Australian bee orchid, Caladenia discoidea. Credit: J. ALCOCK

The book provides evidence for plant evolution at a global level, showing many captivating orchid flowers that are mainly restricted to the southwestern part of Western Australia. Spider orchids, sun orchids, hammer orchids and ‘flying ducks’ serve as examples of remarkable individual adaptations to their pollinators. Alcock explains why this part of Australia has such diversity and discusses the speciation.

Since the publication of Charles Darwin's The Origin of Species, many authors have provided examples in support of natural selection, and others have tried to refute it. This book certainly belongs in the former category, providing vivid examples of adaptation shaped by natural selection promoting reproductive success.

Field biologists face many problems on field trips, such as difficulty in finding the right location and the species they are looking for, and not being sure whether the species they find is new to science or not. Few researchers would transmit this information to others, but Alcock gives a full account of his experience that will be useful for anyone wishing to explore the southwest corner of Australia. I visited Western Australia in the 1980s and was fascinated by the banksias and sundews, for example, that Alcock also mentions. Although I am currently more involved with petaloid monocots, such as aloes, with my interest in orchids this book has inspired me to revisit southwestern Australia when the opportunity arises.

The book is easy to read and has many beautiful illustrations. It shows adaptations found in different groups of plants: orchid flowers lure their pollinators by various means, sundews have folding leaves to capture insects as prey, and plants also rely on winged seeds or the explosion of dried capsules for dispersal.

For an overview of the concepts of adaptation and maladaptation, a brief history of evolution in general, and a good look at the hotspots, biodiversity and conservation of orchids in southwestern Australia in particular, this is the book to read.