Black Nightshade

Black nightshade (Solanum nigrum) is a common upright or erect summer annual or short-lived perennial broadleaf shrub. The plant's leaves are green, ovate to heart-shaped with wavy or large-toothed edges. Stems, leaves, and leaf stalks have some hairs but are not densely hairy or sticky. Stems of perennial black nightshade plants sometimes become slightly woody at the base. From March through October, black nightshade produces four to eight star-shaped greenish to whitish flowers which grow in clusters. It initially develops green berries which transition into a dull black to purple-black color as they mature. The outer portions of the flower cover only a small part of the fruit surface, and sometimes curl away from the fruit.

Toxic components
Black nightshade contains varying levels of steroidal glycoalkaloids. Solanine is the principal toxin, which varies in its content depending on the plant part, season, maturity of plant, and other environmental conditions. Most cases of poisoning have occurred in birds from ingestion of the immature (green) berries and the leaves of nightshade plants. Wilted leaves contain the highest amounts of toxins.