Houttuynia cordata, the source of the herb, is the dried above-ground part of Houttuynia cordata, family Houttuyniaceae. It is harvested in summer when the stems and leaves are lush and the flower spikes are abundant, and the impurities are removed and dried in the sun. Concoction method

Fresh Fritillariae Cordata removes impurities. Dried Houttuynia cordata removes impurities, quickly washed, cut and dried.