Evolution and Ecology of Palms

Abstract

Botanists, including those with an economic bent, and ecologists recognize the importance of palms for a multitude of reasons. As such, palms have been the focus of much research. Tomlinson (1990) provided a solid understanding of palm anatomy and Johnson (1996) outlined issues in palm conservation. Even a fairly thorough review of the economic botany literature pertaining to palms has been compiled by Balick and Beck (1990). Several authors have addressed palm evolution and classification: Moore (1973), Uhl and Dransfield (1987), and Henderson and Borchenius (1999). The last, like many edited volumes, is a spotty treatment of the topic. In this new book Henderson brings us up to date in our present understanding of palm evolution while acknowledging that more data are needed to fill in the many gaps and come to a new understanding of their evolutionary relationships. Given the importance of palms in tropical ecosystems, the lack of a family-based ecological synthesis has been another significant gap in their study. Economic botanists increasingly engage in studies that consider ecological parameters of plant use and management, and palms are frequently the plants of choice. Thus, Henderson’s newest book is a welcome addition on our library shelves. The introductory chapter provides a synopsis and a theoretical framework on which Henderson bases his book, materials and methods, and a summary of the major groups of palms recognized (after Moore). This chapter, plus the next four, review: palm morphology and evolution—stem growth and development; stem size and shape; leaves; and inflorescences. Henderson’s stated emphasis is on stems. He builds his case for their central importance in palm evolution, while acknowledging that he downplays leaves and inflorescences in part because much of their morphology is due to stem size and shape, and also because much has already been published on them. The remaining six chapters address specific ecological aspects of palms: duration of reproduction; phenology of breeding systems; pollination; fecundity and gestation; fruits and seeds—predation and dispersal; and germination. The emphasis here is decidedly on reproduction. Palms have their own terminology and a four page glossary is dutifully provided to assist the uninitiated. The lengthy (21 pages) bibliography is welcome. A 45 page appendix includes 1,245 palm species, arranged by major group, in which Henderson summarizes major morphological traits, germination, habitat, and parity for each. The one page epilogue recapitulates what has proceeded and nicely lays out what Henderson thinks are the most important things to know when considering palm evolution and ecology. Any economic botanist with so much as a passing interest in palms should at the very least take a gander at it (the glossary handily begins on the facing page), and consider well its implications for our studies. Indeed, it would have been wonderful if Henderson had helped us make more connections between people and palms. Alas, he makes only a few passing references. That’s okay. It wasn’t his task. Let’s thank him for his synthesis and work on that part ourselves, made a bit easier, now that he’s provided us with an evolutionary and ecological frame on which to build.