Until now, there has not been a single, full-color guide to some of the most recognizable genera of the southwestern United States: "Agave," "Dasylirion," "Hechtia," "Hesperaloe," "Hesperoyucca," "Nolina," and "Yucca" (the century plants, sotols, false agaves, chaparral yuccas, beargrasses, and yuccas). Some of the species treated in this guide have previously appeared scattered throughout a dozen other field guides, often split roughly between wildflowers and woody plants, or they have been confined to studies of small geographic regions. Still others have appeared virtually nowhere other...