Atropa belladonna is a branching herbaceous perennial rhizomatous hemicryptophyte, often growing as a subshrub from a fleshy rootstock. Plants grow to 2 m (7 ft) tall with ovate leaves 18 cm (7 in) long. The bell-shaped flowers are dull purple with green tinges and faintly scented. The fruits are berries, which are green, ripening to a shiny black, and approximately 1.5 cm (0.6 in) in diameter. The berries are sweet and are consumed by animals that disperse the seeds in their droppings, even though they contain toxic alkaloids (see Toxicity).[13] There is a pale-yellow flowering form called Atropa belladonna var. lutea with pale yellow fruit.
Sometimes A. belladonna is confused for the less poisonous black nightshade, Solanum nigrum, which is in a different genus within Solanaceae. A comparison of the fruit shows that the black nightshade berries grow in bunches, whereas the deadly nightshade berries grow individually. Another distinction is black nightshade flowers have white petals.