Synonyms: Kunzia tridentate, Purshia tridentata var. tridentata, Tigarea tridentate
Close-up of the flowers of antelope bitterbrush as seen along the Old Headquarters Road in the Klickitat State Wildlife Area of south-central Washington...................May 24, 2009.
Bitterbrush is an erect, stiff, and abundantly branched shrub up to 2.5 meters tall. It is freely branched, although under constant grazing, it may be more compact and globose in shape. The young stems are reddish-brown in color, becoming reddish-gray brown with age. The leaves are alternate on short spur shoots off the main stem and deciduous. They are wedge-shaped with 3 rounded teeth at the tip. The leaves range from 10-20 mm in length and are short-haired, with green upper surfaces and gray woolly below. The leaf margins may be rolled under.
The flowers appear singly and are pale yellow in color. The 5 lobes of the calyx are each 6-8 mm long and ovate-oblong in shape. The petals are obovate-oblong in shape or spatulate and 6-9 mm long.
Bitterbrush is an important browse species for hoofed mammals such as mule deer and pronghorn. It was used by native Americans for firewood. Although the seeds are bitter, they are cached or eaten by rodents in large quantities.
Bitterbrush is found in sandy, gravelly, or rocky soils in arid habitats both in the open and in juniper or ponderosa pine forests.
Bitterbrush may be found from British Columbia south along the eastern slopes of the Cascades through Washington and Oregon and mostly along the eastern slopes of the Sierra Nevada to Inyo County California. Eastward, it is found to western Montana, Wyoming, Colorado, and New Mexico.