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

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

4. Brittle and easy to break.

5. The leaves are alternate, the leaves are folded and shriveled, and after flattening, they are heart-shaped, the apex is gradually pointed, and the whole edge.

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 are combined to form a sheath.

8. The spikes are terminal and yellow-brown.