Opium poppy. Illustration of a flowering opium poppy, Papaver somniferum. The flower (red) contains a yellow starfish-like stigma. When the petals fall the stigma and carpel (capsule), are left (as at upper centre). The carpel contains young seeds. It is from the sap of these unripe capsules that crude opium is harvested. Crude opium contains numerous alkaloids including morphine, heroin & codeine. It is used medicinally as a sedative and to relieve pain. However, opium is extensively used as a narcotic drug, forming dependency at an early stage.