The Grand Canyon's isolation, great elevational range, and position at the convergence of three North American Deserts--the Mojave, Sonoran, and Great Basin--have created unique habitats for an unusual assemblage of plants. Some grow at seeps and springs, others emerge from cracks in the bedrock, and still others inhabit sandbars within reach of the Colorado Rivers's scouring currents.River and Desert Plants of the Grand Canyon, the first comprehensive...