Corncockle may also be shown as corn cockle. It is an introduced annual with erect stems from 40-120 cm high from a strong taproot. The stems are simple to branched and covered with fine, white hairs. The pubescent, linear-lanceolate leaves are 5-12 cm long and 3-7 mm wide.
The few flowers are on long pedicels from 5-15 cm long. The calyx lobe is 12-16 mm long and becomes strongly 10-ribbed in fruit. The calyx lobes, which are 20-40 mm long, are linear, leafy and longer both than the calyx tube as well as the petals. The corolla is 2-3 cm across. The petals are purple-red and up to 30 mm long. The petals lack appendages near the base of the inner petal surface.
Corncockle is a weedy species of disturbed ground, including grainfields, wastelands and roadsides.
Introduced from Europe, corncockle is found over much of North America. It is fairly well established in Washington and Oregon but less so into Idaho and Montana.