Isatis tinctoria

Woad, Woad

Family: Brassicaceae · Type: biennial · Not Native

Conservation status: Cal-IPC Yes

Woad is a naturalized biennial found in the Klamath Ranges, northern California Ranges, northern Sierra Nevada, and Modoc Plateau in disturbed areas and pastures at elevations of 100 to 2,200 meters. Flowering from April to July, this plant produces distinctive yellow flowers in small clusters, each petal approximately 2.5 to 4 millimeters long. Growing with tall branching stems 30 to 100 centimeters high that become glaucous and glabrous, the plant develops a robust, spreading structure. Its basal leaves are oblong to oblanceolate, ranging from 6 to 20 centimeters long, with entire or slightly wavy edges that transition to smaller entire cauline leaves along the stem. The plant produces distinctive elongated fruits 1 to 2 centimeters long with reflexed pedicels, characteristic of its weedy, naturalized nature.

Habitat: Disturbed areas, pastures

Bloom period: Apr-Jul

Elevation: 100-2200 m

Bioregions: KR, CaR, n SNH, MP

California counties: Mendocino, Humboldt, Siskiyou, El Dorado, Tehama, Nevada, Placer, Modoc, Yolo, Calaveras, Sierra, Marin, Trinity, Tuolumne, Colusa, Butte, Amador, Glenn, Lassen, Del Norte, Shasta, Napa, Alameda

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