The source of opium used medicinally and illegally in the production of heroin as well as grown as a cultivated ornamental. The latex of some species is used in the treament of warts, for eye disorders and as a dye source for coloring feathers. Flowers are large and borne on an inflorescence of cymes, panicles, umbels or as a solitary flower. Fruit a capsule. Seeds with oily endosperm.
Placentation is parietal to axile.
Leaves are simple and lobed and dissected or entire, alternate. Stipules are lacking.