The rhizome is white, enlarges more than 1 cm in diameter, and extends sideways. The stem stands upright from the underground stem, is a thick quadrilateral, is 76 to 122 cm high, and does not branch. The knot part becomes slightly black, and white hair grows, but there is no hair in the part other than the knot. Leaves are slightly densely facing, with no or short petiole. Leaf blades range from wide needle shape to narrow oval, with a length of 8 to 15 cm and a width of 1.5 to 4 cm. The upper one gradually gets smaller. The leaf tips are sharp, and the edges have rough serrations. The leaf quality is hard, hairless, and shiny. Small flowers are closely attached to the upper leaflets. The spider is 5 to 5 mm long, splits up to the middle, the shard is thin, and the tip is sharpened like a sting. The corolla is white, about 5 mm long, with a short lip shape. There are two upper lips and three lower lips slightly longer than the upper lip. There are two stamens. The fruit consists of 4 parts, and they are wedge-shaped, 2 mm long and wide.