Red-root Yampah

Perideridia erythrorhiza is a rare species of flowering plant in the family Apiaceae known by the common names western yampah and redroot yampah. It is endemic to Oregon in the United States, where there are about 20 occurrences. The populations occur in three regions in southwestern Oregon, which are separated by more than 50 miles (80 km). The three separate groups are in the Klamath Mountains and on either side of the Cascade Range.

This plant is a perennial herb growing up to 1.2 meters (3 ft 11 in) in height. The roots are pink to reddish brown in color. The inflorescence is an umbel of tiny white flowers. Blooming occurs in July through September.