ABSTRACT
Poisonous plants constitute one of the most significant management problems on western and southwestern ranges. J. M. Kingsbury, in an extensive review of poisonous plants in the US and Canada, reported that over 1,000 species are toxic to livestock in some way. Desert Baileya, a small, showy, weak perennial of the sunflower family, is found throughout the southwestern US and Mexico. Spring parsley is confined to the Intermountain Region, primarily in Nevada, southeastern Oregon, southwestern Idaho, and southwestern Utah. Inkweed or thickleaf drymary is a succulent, grayish-green glabrous summer annual found on alkaline clay soil in western Texas, southern New Mexico and Arizona, and Mexico. Pinque or western rubberweed, a thick-rooted perennial herb, inhabits dry soils at elevations of 1,830 to 2,440 m in the mountains and foothills in the Rocky Mountain Region. Chokecherry, distributed widely throughout the western US, continues to be an important poisonous plant to cattle and sheep.
