This guide is the most complete work ever written on the medicinal plants of western North America. It offers the best information in the world on the current popular and traditional uses of the nearly 500 species covered, much of it available for the first time. More than 530 color photographs illustrate the plants and their flowers, leaves, and fruits. The descriptive text combines scientific, ethnobotanical, and cross-cultural information, making this field guide unique. An index to medical topics is helpful for quickly locating information on specific ailments. Symbols next to the plant descriptions provide quick visual warnings for poisonous and allergenic plants. Organized by flower color for fast identification, this guide is an essential aid to appreciating native plants and the wild areas they inhabit.