An easy-to-use, wide-ranging guide to invasive plants in North America. Features full-color photos and descriptions of more than 250 alien species--both terrestrial and aquatic--that are in some cases changing the landscape to an almost unimaginable degree. Accompanying text describes the plant's environmental and economic impacts as well as management techniques used to control it. Also includes an explanation of what an invasive is and a step-by-step identification key. An essential guide to understanding this unprecedented environmental challenge.