Atropa belladonna, commonly known as belladonna or deadly nightshade, is a perennial herbaceous plant in the nightshade family Solanaceae, which includes tomatoes, potatoes, and eggplant. It is native to Europe, North Africa, and Western Asia. Its distribution extends from Great Britain in the west to western Ukraine and the Iranian province of Gilan in the east. It is also naturalised and/or introduced in some parts of Canada and the United States.
The foliage and berries are extremely toxic when ingested, containing tropane alkaloids. These toxins include atropine, scopolamine and hyoscyamine, which cause delirium and hallucinations, and are also used as pharmaceutical anticholinergics.
Atropa belladonna has unpredictable effects. The antidote for belladonna poisoning is physostigmine or pilocarpine, the same as for atropine.
It has a long history of use as a medicine, cosmetic, and poison. Before the Middle Ages, it was used as an anesthetic for surgery; the ancient Romans used it as a poison (the wife of Emperor Augustus and the wife of Claudius both were rumored to have used it for murder); and, predating this, it was used to make poison-tipped arrows. The genus name Atropa comes from Atropos ("unable to be turned aside"), one of the three Fates in Greek mythology, who cut the thread of life after her sisters had spun and measured it; and the name "bella donna" is derived from Italian and means "beautiful woman" because the herb was used in eye-drops by women to dilate the pupils of the eyes to make them appear seductive.