Family: Brassicaceae, Mustard view all from this family
Description Introduced; invasive. A shrubby, herbaceous plant bearing clusters of bright yellow flowers at the ends of branched stems.
Flowers: small; in wide-branching, flat-topped clusters.
Leaves: basal leaves long, hairy. Stem leaves alternate, hairless, stalkless, strap-shaped. Both types of leaves have white midrib.
Fruit: cluster of small, blackish pods, each enclosing 1 seed.
Height: 1-4' (0.3-1.2 m).
Habitat Roadsides, agricultural fields, and other disturbed areas.
Range Native of Eurasia and northern Africa; naturalized in many areas of western North America and scattered areas in the East.
Discussion Dyer's Woad is considered a noxious pest throughout the West. It yields a blue dye; in Europe its blue dye was combined with the yellow yielded by Dyer's Greenweed (Genista tinctoria) to produce a green color widely used for dying wool.