Most of the plant species originating from lowland regions cannot be easily acclimated in alpine regions, because the alpine environments are out of the climatic range in which the lowland species can germinate, grow and reproduce. In some lowland species, however, habitats are distributed over a wide altitudinal range. In general, they inhabit disturbed bare land in alpine regions.
Temperature is an important environmental factor that limits the altitudinal distribution of plants.
Altitudinally widespread species have been used to investigate the adaptive variations within a species to a thermal environment. Ecophysiological studies on the plants growing in mountainous areas are poor in Japan as compared with foreign countries. Reynoutria japonica Houtt. Reynoutria japonica is a perennial, dioecious herb. The adult female plants produce many seeds at the end of the growing season.