annual, herbaceous, tropical plant (Datura stramonium) of the potato family (Solanaceae) that has become an introduced weed throughout much of the Northern Hemisphere. The plant was used by Algonquin Indians in eastern North America as a hallucinogen and intoxicant. The leaves contain potent alkaloids (hyoscamine and hyoscine), and the plant has been used to develop a drug (stramonium) for treating asthma.

Jimsonweed grows to a height of 1 to almost 2 metres (up to 6.5 feet), has large, white or violet, trumpet-shaped flowers, and produces a large, spiny fruit to which the common name thorn apple is sometimes applied.