Continuing in the vein of the author's Pitcher Plants of the Americas (2006), Glistening Carnivores (2008) and Pitcher Plants of the Old World (2009), these two volumes are a testament to Stewart McPherson's fascination with the world of carnivorous plants – few modern authors manage such sustained productivity. As his readers have come to expect, the new volumes are lavishly illustrated with photographs, including many taken by the author, and other pictures. The books include information about all the 20 genera of plants considered to be carnivorous [or at least towards that end of the non-carnivore/carnivore spectrum – some like Roridula do not have all the characters expected of a ‘true’ carnivore (see Chase et al., 2009, for a discussion of what constitutes carnivory)], and Ibicella/Proboscidea (Martyniaceae) and Philcoxia (Plantaginaceae) are tentatively included although their carnivory has not been fully researched or proven.
After a brief introduction, the first main chapter provides a historical perspective of the development of ideas about plants as carnivores. Many found the idea of flesh-eating plants difficult to accept, and it took pioneering work by Darwin and others in the late 19th century to overcome the prejudices involved. This is followed by a chapter summarizing the surprisingly widespread occurrence of carnivory (given its rarity) across the angiosperms (see APG III, 2009; Chase et al., 2009). This chapter concludes with a discussion of ‘sub-carnivorous’ plants i.e. those which can/do trap small animals but for which there is no tangible evidence of full carnivory.
A discussion of evolution of carnivorous plants forms the substance of the next chapter. Based on summarized phylogenetic trees, McPherson discusses the number of times that carnivory has evolved or been lost in the major clades including carnivores. Evolution within each of the carnivorous groups is then discussed, with ideas presented about possible evolutionary pathways leading to the different sorts of traps. The general part of the work concludes with a chapter on ‘associated life’ (animals which live on or around carnivorous plants) and a summary of the habitats in which carnivorous plants can be found.
The remaining (and most substantial) part of the work consists of chapters on each of the genera. These are organised by trap type: snap traps, pitchers, sticky leaves, corkscrew traps and bladders. After introductions to each type of trap, all genera receive individual treatment with the exception of Ibicella and Proboscidea (as these are often treated as a single genus, they are treated in the same chapter). For each, information is provided under the following headings: distribution, botanical history, plant structure, habitats and ecology, traditional uses, associated life, cultivation requirements and conservation status. Again, I can't resist mentioning the rich illustrations that accompany the text in all the chapters, including reproductions of historical plates, habitat shots, stunning close-ups illustrating particular points of interest and photomicrographs depicting details too small to be seen (at least easily) with the naked eye. For the larger genera (Nepenthes, Drosera, Pinguicula), an additional section on species is included.
Expressing his concern for conservation, McPherson concludes the main part of the second volume with a chapter on the future of carnivorous plants and their habitats, covering topics including habitat degradation, over-collection and responsible cultivation. This chapter includes details of several nurseries and their activities related to popularizing and conserving carnivorous plants.
The extensive Appendix mainly comprises five ‘stand alone’ papers. Four are by McPherson and colleagues, in which they describe the new species Nepenthes gantungensis, N. hamiguitanensis, N. holdenii and N. palawensis (each as a separate paper with different authors). These continue the series of spectacular new finds in Nepenthes, including N. attenboroughii (Robinson et al., 2009), described by this group. The fifth paper (by F. S. Mey) provides historical background to the ‘elusive’N. thorelii and an amended description based on new material. The second volume concludes with a glossary, bibliography and index.
As with his previous works, I recommend these volumes enthusiastically to carnivorous plant enthusiasts in particular and botanists and botanical institutions in general. Full of interesting facts and wonderful illustrations, they are very good value for money, as well as being attractive additions to the literature relating to carnivorous plants.