The Peterson Field Guide to Western Medicinal Plants and Herbs is one of the most complete works on the medicinal plants of western North America, offering some of the best information in the world on the nearly 500 species covered. More than 530 color photographs illustrate the plants. An index to medical topics helps locate 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.