The Black nightshade (Solanum nigrum) belongs to Solanaceae (the Nightshade family). It is an annual plant that is distributed widely, throughout Japan and the northern hemisphere. This herb grows generally on roadsides and fields, and can reach 30-60 cm in height. Leaves are broad ovate with wavy-toothed edges. From August to October, 4 to 8 small white flowers with a diameter of 6-7 mm bloom in a raceme. Fruits are round berries, 7-10 mm across, and ripen matt purplish-black. The plant contains toxic solanin, and the fruits contain toxic fatty oils.