The plant grows 30 - 150 cm high and can form a fleshy taproot. The upright, hollow stem is branched upwards.
All leaves, including the lower ones, are blue-green and have bristles on the underside, at least at the midrib. In turnip rape the lower leaves are grass-green and bristly. The upper leaves are stemmed with a shallow heart-shaped base. In turnip rape, the upper leaves have a stemmed, deep heart-shaped base. The lower, lanceolate leaves have a up to 15 cm long petiole and a 5 - 25 cm long and 2 - 7 cm wide leaf blade. The leaf blade is often undivided or has up to 6 pinnate lobes. The terminal lobe is ovoid and has a serrated edge. The other lobes have a serrated or unserrated margin.
In the wild, rapeseed flowers from April to August.