The Encyclopedia of Invasive Species, in 2 volumes, provides a clearly presented and well-organized introduction to invasive species and, briefly, to the history of invasion science. The eighty-eight entries in volume 1 address invasive microorganisms, fungi, and animals and are arranged alphabetically within their major taxonomic groups (microorganisms, fungi, invertebrates, and vertebrates). The eighty plant entries in volume 2 are arranged by growth form categories (aquatics, forbs, graminoids, shrubs, trees, and vines). The general introduction contained in volume 1 explains what might constitute an invasive species and discusses the various issues that arise from inconsistent uses of terms to describe invasive and nonnative species. Excellent examples of the impact of invasive species of all types are presented in the general introduction, whereas a brief overview in volume 2 emphasizes invasive plants. Volume 2 contains a table of common and scientific names and several appendixes listing American species that are invasive elsewhere, laws related to prevention and management, international agreements, the IUCN's list of 100 of the “World's Worst Invasive Alien Species,” and a selected bibliography. Both volumes include a state-by-state list of occurrences of invasive species, a glossary, and a comprehensive index.

The 168 species included in the encyclopedia were selected in order to represent and illustrate a wide variety of invaders in the United States. Some of the species included have been present from colonial times, while others have only recently become established. Entries include species found throughout the country as well as some that are extant in only a few areas or states. In order that room could be made for invaders of all states, those states with the highest numbers of invaders such as Hawaii or Florida will not find all of their invasive species listed.

Each entry includes the following information about the organism: native range, US distribution, description, related and similar species, introduction history, habitat, diet (for animals), life history (for animals, fungi, microorganisms only), reproduction and dispersal (for plants), impacts, management, and selected references. Black and white photographs of the organisms are present for many of the entries, and maps showing the original and invasive range are included for all. A short bibliography of recommended resources, including websites, concludes each entry. In volume 2, sidebars highlight interesting facts about the plant's use, history, or strategies for control.

Woodward and Quinn's work focuses on the 168 species they have chosen for inclusion. In comparison, the recent single-volume Encyclopedia of Biological Invasions edited by Simberloff and Rejmánek (University of California Press, 2011) contains articles on broader topics such as “integrated pest management” and “evolutionary response, of natives to invader” rather than species-specific entries. Both resources are available in print or electronic version and would complement each other in a reference collection.