Perennial herbs on swampy forest ground near streams. Bloom in late spring after trees shoot out buds. The fan-shaped calyx after flowering resemble the hoe-shaped helmet crest (Kuwagata), hence the Japanese name Kuwagata-so. Color of flowers is light red-purple and bloom one to five from the base of leaves on upper parts of stems. The size of flower is 1 cm in diameter and has some purple lines radiating from the center of petals. The dish-shaped corolla is parted, making flowers have four petals. Leaves are opposite with two leaves. The shape of leaves is egg-shaped with pointed tip and roughly toothed margins. The ones towards tips of stems are large and about 3 to 5 cm. Stems and leaves have short hairs.

●Season　　Early May to about Early June
●Height　　about 10 to 20 cm
●Place　　Trial 6, Ura-Takao