Solanum nigrum is an annual herb with a height of 30 ~ 60 cm. Stems erect or prostrate, angular, sparsely white pilose along the edges and corners. Leaves alternate, ovate, broadly cuneate or nearly truncate at base, tapering to petiole, apex pointed or long pointed; The leaf size varies greatly, usually 4 ~ 7 cm long and 3 ~ 5 cm wide, and the largest one can reach13～5cm long and 7 cm wide; The leaf margin is undulate and serrate, with about 3 ~ 4 teeth on each side, about 5mm in width and 3 ~ 4 mm in length; The petiole length is15 ~ 35 mm, and the stalk length of big leaves can reach 5cm. Umbrella cymes are lateral, with drooping flower stalks, each inflorescence has 4 ~10 flowers, and the flowers are white; Calyx cylindrical, sparsely covered with fine hairs, lobes 5, ovoid triangle, about 3 cm; Corolla hairless, lobes extending in a wheel shape, 5 pieces, oblong-ovoid; Stamens 5, inserted into the mouth of corolla tube, filaments separated, and villous inside; Pistil 1, ovary 2-loculed, spherical, white fuzz in the lower part of style, round stigma. Berries are spherical, shiny, about 8mm in diameter, and red or black when ripe. The seeds are oblate, and the flowering and fruiting period is 9 ~10 month. The roots (roots) and seeds (seeds) of this plant are also used for medicine. All herbal medicines can clear away heat and toxic materials, promote diuresis and reduce swelling, and treat colds, fever, toothache and bronchitis. Solanum nigrum lime mixture can kill cotton aphids up to 80%; The twigs are used as pig feed. The whole grass contains solanine, solanine and other alkaloids. It is the aerial part of Solanum nigrum L., a Solanaceae Solanum plant, and is used as medicine by whole grass. Harvest in summer and autumn, fresh or dried. It mainly harms cotton, beans, potatoes, melons and vegetables.