Over-two thirds of the U.S. population is allergic to poison oak, poison ivy, or a related plant. These and many other common plants in our homes, fields, and gardens are irritants that cause misery to many. But surprisingly, there has never been a general guide to help raise awareness of them–and to help avoid them. This new book reviews the history, occurrence, classification, toxicity, and health aspects of all the major allergenic and irritant species.