Herbaceous annual up to 1 m. Large lower leaves, broadly oblong or obovate with serrated margins, the upper leaves are cauline, simple, narrower, lobed, dentate or entire, short petioles or sessile. Bright yellow flowers of 7 to 10 mm. Fruit in the form of a pod 4 to 7 cm long, dark brown seeds up to 2 mm in diameter.