The "Gaga-imo" (Metaplexis japonica) belongs to the Asclepiadaceae (the Milkweed family). It is a perennial herb that is distributed throughout Japan, as well as to the temperate and warm-temperate areas of East Asia. This herb grows in fields and spreads by trailing rhizomes. The leaves are long-ovate-cordate and opposite. The racemes are borne on the long peduncles and bloom pale purple flowers in August. The pollens form the pollen mass. The fruits are follicles and the seeds are carried on the wind. The young shoots and fruits are edible and the leaves are used for tonic medicine. In Chinese, it is called "蘿藦" (luo mo).