Perideridia howellii

Howell's yampah

Family: Apiaceae · Type: perennial · Native

Howell's yampah is a California native perennial found in the Klamath Ranges, northern Coast Ranges, Cascade Range, northern Sierra Nevada, and central Sierra Nevada Forest in moist meadows, ravines, and streambanks at elevations of 100 to 1,500 meters. Flowering from July to August, this plant produces white flowers in delicate umbels with 17 to 20 spreading rays. Growing 80 to 160 centimeters tall with fibrous roots clustered in groups of more than 15, it develops substantial lanceolate basal leaves up to 50 centimeters long that are intricately 2-pinnate. Its leaves feature deeply toothed leaflets 2 to 7 centimeters long, with distinctive linear-spoon-shaped bracts that have scarious margins and are reflexed. The fruit is an oblong structure 4 to 6 millimeters long with conspicuously corky ribs and a single oil tube between each rib.

Habitat: Moist meadows, ravines, streambanks

Bloom period: Jul-Aug

Elevation: 100-1500 m

Bioregions: KR, NCoRO, CaR, n SN, c SNF

California counties: Siskiyou, Sierra, Plumas, Sonoma, Butte, Colusa, Tehama, Mendocino, Humboldt, Lake, Nevada, Del Norte, Mariposa, Calaveras, Shasta

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.