A long white rhizome extends from the rhizome, and many roots grow on the root of the rhizome. The stem is upright without branching, is square, is 15 to 60 cm in height, has no hair on the stem, and has hair only on the nodes. Leaves are opposite, leaf blades are slender egg-shaped to folding needle shape, length 2 to 4 cm, width 1 to 2 cm, leaf tip is sharp or blunt, base gradually thins into long petiole, on edge Has a blunt and coarse sawtooth. The surface of the leaves is almost hairless, dull, and has fine glands. Several small flowers are densely attached to each leaflet. The scissors are about 3 mm long, and are split into 5 to the middle. The corolla is white, about 3 mm long, and 4 points apart. There are 2 stamens and 1 stamen. The fruit consists of 4 fruits, and the fruits become a wedge-shaped tetrahedron with a length of about 1.5 mm.