Chinese: hu zhang
English: Japanese knotweed
Pharmaceutical: Polygoni cuspidati Rhizoma
Properties: Bitter, cold
Standard Species: Polygonum cuspidatum Sieb. et Zucc., Reynoutria japonica Houtt. var. japonica

Japanese Knotweed (Polygonum cuspidatum) - Hamilton, Canada (Photo by TH Tanaka)

Japanese Knotweed (Polygonum cuspidatum) - Hamilton, Canada (Photo by TH Tanaka)

Reynoutria sachalinensis - Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan (Photo by TH. Tanaka)