The Bogbean (Menyanthes trifoliata) belongs to the family Menyanthaceae. It is a perennial herb that is distributed throughout Japan, as well as to the Northern Hemisphere widely. It is a relict plant of glacial age. This herb grows in shallow waters of marshes and streams in cold climates gregariously, and can reach 20-50 cm in height. The rhizomatous roots are thick and spread by creeping on the grounds. The leaves are trifoliate and divided into oblong lobes. The white flowers bloom in the racemes from April to July. The plant is a great favorite of cats as well as the silver vine. In Chinese, it is called "睡菜" (shi cai).