“What is a ” opined Emerson, “but a plant whose virtues have not yet been discovered?” While that may be a worthy notion in theory, these plants of undiscovered virtue cause endless hours of toil for backyard gardeners. Wherever they take root, weeds compete for resources, and most often win. They also wreak havoc on industry—from agriculture to golf courses to civic landscape projects, vast amounts of money are spent to eradicate these virile and versatile invaders. With so much at stake, reliable information on weeds and their characteristics is crucial. Richard Dickinson and France Royer shed light on this complex world with the essential reference for all who wish to understand the science of the all-powerful weed. Encyclopedic in scope, the book is the first to cover North American weeds at every stage of growth. The book is organized by plant family, and more than five hundred species are featured. Each receives a two-page spread with images and text identification keys. Species are arranged within family alphabetically by scientific name, and entries include vital information on seed viability and germination requirements. Whether you believe, like Donald Culross Peattie, that “a weed is a plant out of place,” or align with Elizabeth Wheeler Wilcox’s “weeds are but unloved flowers,” Dickinson and Royer provide much-needed background on these intrusive organisms. In the battle with weeds, knowledge truly is power. is the perfect tool for gardeners, as well as anyone working in the business of weed ecology and control.