San’inshiroganesou, or  Dichocarpum nipponicum var. sarmentosum, is a perennial occurring in damp places by a mountain river. It resembles another species in the same genus. Still, the difference is clear because it provides a dark-purple crest at the base of each petaloid sepal, which characterizes this species. As for petals, they are the yellow portions in flowers. After flower, this species spreads runners to make new growth.