About Purshia tridentata (Pursh) DC.
Purshia tridentata (Pursh) DC. is a deciduous shrub that reaches 1 to 5 metres (3+1⁄2 to 16+1⁄2 feet) in height. It produces many branches and slender green leaves that are 5 to 20 millimetres (1⁄4 to 3⁄4 in) long, with three to five lobes per leaf. This species is a nitrogen-fixing plant. Its flowers are pale yellow, with five petals 6–8 mm long and darker yellow anthers. Its fruit is a cluster of dry, slender, leathery achenes, where each achene grows up to 1 centimetre (1⁄2 in) long. This plant is distributed across a wide geographic range: it extends north to southeastern British Columbia, east to Montana and Wyoming, south to New Mexico, and west to California. It grows on arid mountainsides and slopes, in addition to rocky or drained soils that hold somewhat more moisture than soils in sagebrush steppe. It is often found growing alongside Balsamorhiza and Wyethia species, and in its southern range it hybridizes with Purshia stansburyana. In California, it occurs between 700–3,400 m (2,300–11,200 ft) above sea level, including in the Peninsular Ranges, Transverse Ranges, Sierra Nevada, and southern Cascade Range. In more northern parts of its range, it grows at lower elevations, for example at 320–1,065 m (1,050–3,494 ft) in British Columbia. Ecologically, this shrub is an important forage plant for many game animals, including deer, particularly during the winter.
