Armoracia rusticana

Horse radish

Family: Brassicaceae · Type: perennial · Not Native

Horse radish is a naturalized perennial found in the Central Valley, central Coast, and San Francisco Bay regions in ditches, roadsides, moist places, and fields at elevations below 1,100 meters. Flowering from March to July, this plant produces white flowers 5 to 7 millimeters long with obovate petals. Growing with generally erect, branched stems 5 to 12 decimeters tall, it develops deep roots that spread vigorously. Its basal leaves are wide-oblong to ovate, 1.5 to 12 decimeters long with crenate edges, while stem leaves are pinnately lobed and become progressively smaller toward the stem tip. The fruit is small, typically 4 to 6 millimeters long, and rarely produces viable seeds.

Habitat: Ditches, roadsides, moist places, fields

Bloom period: Mar-Jul

Elevation: < 1100 m

Bioregions: GV, CCo, SnFrB

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