2. Saururaceae plants, which are produced in the provinces south of the Yangtze River valley in China.

3. The stems of Houttuynia cordata Thunb are oblate and twisted, with brown surface, several longitudinal edges and obvious nodes, and there are residual fibrous roots on the lower nodes.

4. Fragile and easily broken.

5. Leaves alternate, folded and shriveled, heart-shaped after flattening, with tapering apex and entire margin.

6. The upper surface is dark yellow-green to dark brown, and the lower surface is grayish green or grayish brown.

7. The petiole is slender, and the base and stipules combine to form a sheath.

8. The spike is terminal and yellowish brown.