This paper describes Reynoutria as a newly recorded genus of Dock Family (Polygonaceae) to Turkey. Specimens of R. japonica Houtt. (Polygonaceae) were collected from Terme/Bazlamac (Samsun). Adding this new genus, the number of genera in Turkish Flora reached to 11 and the identification key for genera of Polygonaceae was updated. In addition, Turkish name, detailed description, photographs, locality information and geographical distribution map of the species were given in the present study.