The origin of Hu Zhang (Polygonum Cuspidatum) is Japan, China and Korea. Hu Zhang, commonly known as Japanese knotweed is a bare perennial herb with numerous hollow up straight stems up to 3 m tall, rarely branched in the upper part, longitudinally lined, often with reddish-purple spots. The rhizome is thickened, highly branched, and ligneous, with ring-shaped structures. The leaves on both sides are devoid of any pubescence, a little leathery, ovate to wide elliptical in shape. The fruit is 2-4 mm long, about 2 mm wide, brilliantly black or dark brown.