Plants germinate or sprout in fall, are green during the winter, and produce flowers and seed in the spring and early summer. Plants
usually die back with summer heat. The stems are erect, 1 m tall, branched, hairy, and usually bluish-green in color.
Leaves are light to medium green, hairy or bristly, stalked, and are 30–50 cm long. Like most mustards, leaves tend to feel rough due to the stiff hairs on the leaf surface. Leaves are often ravaged by insects and often appear with holes or eaten portions missing.
The flowers have four petals that form a cross.
Flower Seed Head:
Flowers bright yellow; petals 6–10 mm long; those in maturity close together and commonly overtop the unopened buds; outer 2 stamens are much shorter than inner stamens.
Fruit is 4–6.5 cm long with long tapering beak. Seeds are blackish or reddish-brown and 1.5–2 mm in diameter.
Found along roadsides and waste areas. A common weed of agricultural fields.