Paper floras: how long will they last? a review of FLOWERING PLANTS OF THE NEOTROPICS

Flowering Plants of the Neotropics compiled and edited by a team of leading botanists at the New York Botanical Garden (Smith et al., 2004) is magnificently illustrated and rich in authoritative data about the 284 native families of tropical angiosperms currently found in the Western Hemisphere. Compiling information from over 150 contributors and specialists on various groups of plants was clearly a task of significant dimension and the authors are to be congratulated for their contribution to the literature on neotropical flowering plants. This volume follows on the heels of other contemporary contributions to this subject, such as Maas and Westra's (1998) more modest treatment on neotropical plant families, Al Gentry's (1996) wide ranging and highly idiosyncratic tome on plants of northwestern South America (also widely applicable throughout the neotropics), the very detailed field guide to the plants of the Ducke Reserve near Manaus in Amazonian Brazil (similarly of considerable value throughout the Amazon Basin), and finally the "in progress" manual of plants of Costa Rica orchestrated by Hammel, Grayum, Herrera and Zamora (2003) that will serve as the gold standard for national tropical floras when completed. These publications collectively tell us that we know a surprising and considerable amount about the flowering plants of the tropical Americas. This most recent contribution by Smith and colleagues (2004) hovers between a taxonomic monograph and a typical flora in that on the one hand it provides an in-depth treatment of a specific monophyletic group of plants (the angiosperms), but on the other it is restricted in scope to only those taxa found in a distinct geographic region, the neotropics. All things being considered one would have to categorize this broad-based reference volume as a family-level flora of the neotropics. In general we use floras for the purposes of inventory (knowing what taxa are present in an area), identification (knowing the names of the taxa we find or study), description (knowing more about the taxa than we currently do), and classification (knowing how taxa are related to other taxa within as well as outside the focal region). Published floras (as those cited above) vary in their success in providing information in each of these four categories. How does Flowering Plants of the Neotropics compete as a flora with respect to these criteria? The authors have done a great job in the first three categories (inventory, identification, and description), but have partially failed in the fourth (classification). The work is quite comprehensive in the inclusion of all 284 families that have any native taxa represented in the neotropics as well as important introduced species and cultivars. The keys (grouped in an appendix) and illustrations (including 308 color photographs and 258 black and white line drawings) together provide a generally reliable means of identification of plants to family and in some cases to genera (although a few seem misplaced, e.g., Piriqueta for Turnera) and even species (as far as I have been able to attempt although I haven't used it extensively yet in the field for reasons noted below). For each family treatment we are provided with information and notes on critical morphological features, taxonomic diversity, distribution and habitat, classification, natural history, and ethnobiologial uses; some critical literature references are also included. These data provide a wealth of information about each family that allows the reader to put the particular plant family into an ecological, geographical, and economic framework. The extensive illustrated glossary is a luxury. And if one wants to know how Arthur Cronquist (1981) and Rolf Dahlgren (and colleagues; 1985), two renowned but now deceased authorities on angiosperm classification, circumscribed and classified neotropical dicot and monocot families, respectively, then the co-editors might consider that they have succeeded in the fourth purpose of floras as well. This last point identifies one of the most curious, and perhaps disappointing, aspects of the volume. In the age of molecular systematics and the growing acceptance of a new consensus classification of the flowering plants by the Angiosperm Phylogeny Group (1998, 2003; hereafter APG), why have Smith and co-editors regressed to the classifications and circumscriptions of Cronquist and Dahlgren? They claim that using the older systems makes "identification of neotropical plants to family a great deal easier." But does it? Or is it just easier for those who have used these former systems for two decades? And if that is the case, why not go back to Engler and Prantl's (1887-1915) system which has been effectively used for a century? Admittedly, the APG, which has in large part resulted from new insights about relationships gained from DNA sequence data, recognizes a number of segregate families, e.g., in the lilioid monocots, and aggregate families, e.g., the Malvaceae sensu lato, that are defined by anatomical, biochemical, and developmental characters, but lack easily distinguishable diagnostic morphological features useful in identification. However, only when we start working within the framework of a new classification will we ever discover new characters and new relationships to use for such purposes. The co-editors state that they wish "to provide Smith, Mori, Henderson, Stevenson, and Heald [eds.]. Princeton University Press, Princeton, New Jersey, USA. ISBN 0-691-11694-6. The author thanks P. Belhumeur, D. Jacobs, S. Feiner, R. Ramamoorthi, R. Russell, K. Wurdack, L. Weigt, D. Janzen, V. Funk, and W. Wagner for helpful discussion in preparing this review. 3 Author for reprint requests (phone: 202-633-0920; FAX: 202-786-2563; e-mail: kressj @si.edu).