Opium is a resin extracted from the flowering plant Papeverum somniferum during certain stages of its cultivation. Crude opium can be smoked or eaten as a recreational drug, but its alkaloids are more commonly extracted into potentially abusable pharmaceutical forms such as morphine or codeine, or the less medicinally used but more abused heroin. Other variants of the species are grown as ornamentals, or food flavorings, and even the opium poppy has a lovely flower.
Opium cultivation is a large part of the world's illicit drug trade.
The more purified, or such as heroin, chemically modified opium alkaloids have structure-activity relationships with opioid receptors. Not all opium-derived compounds are abusable.
A celebrated account of the pleasures and pains of opium addiction is given in The Confessions of an English Opium-Eater (1822, enlarged 1856) by Thomas de Quincey. His contemporary Samuel Taylor Coleridge also suffered from opium addiction.