nightshade

Nightshade is a common name applied to a broad group of plants in the plant family Solanaceae. The term covers both toxic species and several widely cultivated crops, and it is often used to describe plants with alkaloids that can affect the nervous system. Notable examples include deadly nightshade (Atropa belladonna), black nightshade (Solanum nigrum), bittersweet nightshade (Solanum dulcamara), and a range of cultivated crops such as tomato (Solanum lycopersicum), potato (Solanum tuberosum), eggplant (Solanum melongena), and peppers (Capsicum species).

Toxicity and chemistry vary widely within nightshades. Many species produce alkaloids that can be poisonous in certain parts or under certain conditions. Atropa belladonna contains tropane alkaloids such as atropine and scopolamine, while other Solanaceae produce solanine or capsaicinoids. Edible members, when prepared properly, are widely consumed, but ingestion of unripe fruit, leaves, or green parts can be harmful. Cooking and processing often reduce or remove some toxins in edible species.

Uses and cultural context also vary. Some nightshade plants are cultivated for food, ornamental value, or both. Tomatoes, potatoes, eggplants, and peppers are central crops in many cuisines, while ornamental Solanaceae are prized in gardens. Historically, Atropa belladonna has been used in medicine and cosmetics in small, controlled doses, but it is deadly in larger quantities. Because the term covers a diverse set of species with differing properties, accurate identification is important when handling or consuming any nightshade.