This association includes species-poor stands dominated by Reynoutria japonica and R. sachalinensis, tall broad-leaved herbs of eastern Asian origin, and their hybrid R. .bohemica. It occurs mainly on river banks, but it is also common on roadsides, along railways, in waste places and abandoned meadows. Reynoutria species intensively spread to new sites via vegetative propagules and once established, they move to dominate the sites through intensive clonal growth. Invasion of Reynoutria species in the Czech Republic started in the middle of 20th century. Their monodominant stands are scattered to common from lowlands to submontane areas across the country. The hybrid tends to be more invasive than its parent species.