Papaver somniferum is an annual herb growing to 100 cm. All parts of the plant are strongly glaucous, giving a greyish-green appearance, and the stem and leaves are sparsely covered with coarse hairs. The leaves are lobed and clasp the stem at the base. The flowers are up to 120mm diameter, normally with four white, mauve or red petals, sometimes with dark markings at the base. The fruit is a hairless, rounded capsule topped with 12–18 radiating stigmatic rays. All parts of the plant exude white latex when wounded.