Prairie Species Habitat Conservation Plan – Bradshaw’s Lomatium

Lomatium bradshawii

​​Status

Bradshaw’s lomatium was listed under the Federal Endangered Species act as endangered in 1988. The species is also listed as endangered by the state of Oregon.

Description

Bradshaw’s lomatium is a perennial forb and member of the carrot or parsley family (apiaceae).Plants are low-growing (10-30 cm) and have highly dissected leaves and yellow flowers in an umbel inflorescence.

Bradshaw’s lomatium produces flowers in April and May, and matures seeds, its only means of reproduction, in June.

Several other species of lomatium occur in the Willamette Valley. These include barestem biscuitroot (Lomatium nudicaule), common lomatium (L. utriculatum), and nineleaf biscuitroot (L. triternatum). These species can usually be differentiated from Bradshaw’s lomatium by leaf shape or habitat.

Range and Habitat

Most known occurrences of this species are in southern Washington and the Willamette Valley of Oregon. Habitat for this species includes seasonally saturated wetlands and valley bottom prairie that is dominated by tufted hairgrass (Deschampsia caespitosa). Both of these habitat types were once widespread in the Willamette Valley, and are now extremely rare.

Threats

Remaining populations of Bradshaw’s lomatium are at risk from:

• Further habitat loss or fragmentation
• Invasion of wet prairie habitats by non-native species such as reed canary grass
• Encroachment of trees and shrubs into prairie habitats
• Elimination of natural disturbance regimes