Atropa bella-donna, commonly known as deadly nightshade or belladonna, is a toxic perennial herbaceous plant in the nightshade family Solanaceae, which also includes tomatoes, potatoes and eggplant. It is native to Europe and Western Asia, including Turkey, its distribution extending from England in the west to western Ukraine and the Iranian province of Gilan in the east. It is also naturalised or introduced in some parts of Canada, North Africa and the United States.

The foliage and berries are extremely toxic when ingested, containing tropane alkaloids. It can also be harmful to handle and/or touch these plants. These toxins include atropine, scopolamine, and hyoscyamine, which cause delirium and hallucinations, and are also used as pharmaceutical anticholinergics. Tropane alkaloids are of common occurrence not only in the Old World tribes Hyoscyameae (to which the genus Atropa belongs) and Mandragoreae, but also in the New World tribe Datureae—all of which belong to the subfamily Solanoideae of the plant family Solanaceae.

Consumption of Atropa bella-donna has unpredictable effects. The antidote for belladonna poisoning is physostigmine or pilocarpine, the same as for atropine.

The highly toxic ripe fruit can be distinguished from that of black nightshade (Solanum nigrum) by its larger berry size and larger stellate calyx (with long, broad and somewhat accrescent lobes protruding beyond the fruit) and the fact that A. bella-donna bears its berries singly, whilst S. nigrum bears spherical berries resembling tiny tomatoes in umbellate clusters.

...