Purshia tridentata aka Antelope Bitterbrush

Purshia tridentata is a woody shrub in the rose family. Its common names include bitterbrush and antelope bitterbrush. It grows across western Canada and the western United States. Its range also reaches the west-central United States. Oregon lies within its native range. It occurs in the Cascades, Sierra Nevada, and Rocky Mountains. Its range also includes the Great Basin, Arizona, and New Mexico. Kew places this species in the temperate climate zone.

This shrub has an upright form with many branches. It usually reaches 3–4 feet (0.9–1.2 m) tall. The wider reported range is 2–10 feet (0.6–3 m). Its shape varies across its range. Some plants have several stems that lean along the ground. This form occurs most often at higher sites. Others have one main stem and a narrow, upright shape. Thin bark ranges from gray-brown to brown. Young twigs are slender, smooth, and reddish brown. They turn a grayer brown as they age.

The small leaves give useful clues to its identity. Each leaf has a wedge shape and three tip lobes. Leaves grow in an alternate pattern along the stems. They often form tight groups on short spur shoots. Their edges curl under, and their stalks are very short. Fine hairs cover both sides of each leaf. The upper side looks green or gray-green. The lower side looks white or grayish white. Most plants shed their leaves, though some retain them. Unlike similar-looking big sagebrush leaves, these leaves lack a scent.

Small yellow flowers grow singly where leaves meet the stem. Each flower forms a tube with petals that flare outward. Flowers measure about 0.026 feet (0.008 m) across. The fruit consists of one or two dry achenes. Each achene has an oval or teardrop shape. Its tip narrows into a point or short beak. Sources describe both the fruit and twigs as bitter. This taste alone does not establish food safety or toxicity.

In cultivation, bitterbrush needs sun and a dry site. Its very long taproot supports its drought resistance. Oregon State lists cold hardiness to USDA Zone 3. Its branched form and gray-green leaves suit dry-site planting. The supplied sources give no specific pest or disease guidance.