Black nightshade is a fairly common herb or short-lived perennial shrub, found in many wooded areas, as well as disturbed habitats. It has a height of 30–120 cm (12-48"), leaves 4-7.5 cm (1 1/2-3") long) and 2–5 cm wide (1-2 1/2"); ovate to heart-shaped, with wavy or large-toothed edges; both surfaces hairy or hairless; petiole 1–3 cm (1/2-1") long with a winged upper portion. The flowers have petals greenish to whitish, recurved when aged and surround prominent bright yellow anthers. The berry is mostly 6–8 mm (1/4-3/4") diam., dull black or purple-black.
The black ripe berry can be poisonous, but low toxicity variants are directly consumable and the leaves are cooked and consumed. In India, another strain is found with berries that turn red when ripe.
Red Makoi or Solanum nigrum berries attached to the stalk with green unripe berries that are believed to be poisonous whereas the ripe "Red Makoi" is edible and is often used in anti-inflammatory medicine.All parts of the plant are poisonous containing solanine and other related glycoalkaloids; the toxins are most concentrated in the unripe green berries. Initial symptoms of toxicity include fever, sweating, vomiting, abdominal pain, diarrhea, confusion, and drowsiness. These symptoms are typically delayed for 6 to 12 hours after ingestion. The glycoalkaloid solanine is extremely toxic, and can be fatal. Death can result from the ingestion of high doses of plant parts, causing cardiac arrhythmias and respiratory failure.
The toxicity of Solanum nigrum varies and there are some strains which have edible berries when fully ripe.
In India, the berries are casually grown and eaten; but not cultivated for commercial use. The berries are referred to as "fragrant tomato," or மணத்தக்காளி - manathakkaali in Tamil, Kamanchi in Sanskrit and Telugu, and makoi in Hindi. Although not very popular across much of its growing region, the fruit and dish are common in Northern Tamil Nadu, Southern Andhra and Southern Karnataka. In North India, the boiled extracts of leaves and berries are also used to alleviate the patient's discomfort in liver-related ailments, including jaundice.
In Ethiopia, the ripe berries are picked and eaten by children in normal times, while during famines all affected people would eat berries. In addition the leaves are collected by women and children, who cook the leaves in salty water and consumed like any other vegetable. Farmers in the Konso Special Woreda report that because S. nigrum matures before the maize is ready for harvesting, it is used as a food source until their crops are ready. The Welayta people of the adjacent Semien Omo Zone do not weed out S. nigrum that appear in their gardens since they likewise cook and eat the leaves.
Red Makoi or Solanum nigrum berries used for Therapeutic purposes and as an anti-inflammatory medicine.The plant has a long history of medicinal usage, dating back to ancient Greece. This plant is also known as Peddakasha pandla koora in Telangana region. This plant's leaves are used to treat mouth ulcers that happen during winter periods of Tamil Nadu, India. Chinese experiments confirm that the plant inhibits growth of cervical carcinoma (Fitoterapia, 79, 2008, № 7-8, 548-556).