Biennial or perennial herb to about 1 m tall. Leaves to about 10 cm long, oblong to lanceolate, entire to toothed, lowermost ones 'eared' at the base. Flowers in spring. Fruit 1-2 cm long, pendulous.
The blue dye woad was once extracted from the fermented leaves (although it is more clearly visible in the fruits) but has now been replaced by indigo and other synthetic dyes. Purportedly used as a warpaint by the ancient Britains.
Source: (1997). Brassicaceae. In: . Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.