Solanum is a diverse and large flowering plant genus that includes 3 food crops of great economic importance: eggplant, tomato, and potato.
Also, it contains horse nettles, nightshades, and many plants grown for their ornamental blooms. Solanum species feature various growth forms, such as annual and perennial, small trees, shrubs, subshrubs, and vines.
In addition, many hitherto independent genera such as Cyphomandra and Lycopersicon (tomatoes) are now included as sub-genera or sections in Solanum. Therefore, the Solanum genus now contains around 1, 500 to 2, 000 species of plants.
The species most commonly referred to as nightshade in the UK and North America is Solanum dulcamara, also known as Woody nightshade or bittersweet.
Its leaves and egg-shaped red fruits are poisonous; the active ingredient is solanine, which, if swallowed in large doses, can cause seizures and death. Black nightshade (Solanum nigrum) is usually considered poisonous.
Still, its fully ripe fruits and leaves are eaten and cooked in certain areas. The deadly nightshade (Atropa belladonna) does not belong to the genus Solanum but belongs to the nightshade family. Its flowers are available in white, lavender, and dark purple.