Sophora flavescens, the shrubby sophora, is a species of plant in the genus Sophora a genus of the Fabaceae family, that contains about 52 species, nineteen varieties, and seven forms that are widely distributed in Asia, Oceanica, and the Pacific islands.About fifteen species in this genus have a long history of use in traditional Chinese medicines. The root is known as Ku shen. is a typical traditional Chinese medicine.