Wild cabbage

Brassica oleracea

Wild B. oleracea is a tall biennial plant, forming a stout rosette of large leaves in the first year, the leaves being fleshier and thicker than those of other species of Brassica, adaptations to store water and nutrients in its difficult growing environment. In its second year, the stored nutrients are used to produce a flower spike 1 to 2 metres (3–7 ft) tall bearing numerous yellow flowers.