"Yanone-gusa" (Persicaria nipponensis) belongs to Polygonaceae (the Knotweed family). It is a perennial herb that is distributed all over Japan, as well as the Korean Peninsula and the northeastern part of China. This herb grows on watersides and swamps and is about 50 cm in height. The lower part of the stalk crawls on the ground and has small downward spines. The leaves are ovate to broard lanceolate, alternate, with pointed tips. The flowers are crimson at the top and white at the bottom, and bloom on the terminal branches from September to October. The Japanese name is similar to the shape of a leaf.