The plant morphology is panicum miliaceum, with a height of 30 ~ 100 cm, which is fragrant. The stems are square, pubescent, purplish at the base and much branched at the upper part. The leaves are opposite, 3-5 pinnately parted, and the lobes are strip-shaped or lanceolate, with a length of1.5-2 cm and a width of1.5-4 mm, with pilose on both sides and glandular spots below; Almost sessile. Cymbal flower, integrated with terminal 2 ~ 1.3 cm discontinuous false spike; Calyx narrowly bell-shaped, hairy, calyx teeth triangular-lanceolate; Corolla blue-purple, 2-lipped, longer than calyx, middle lobe apex of lower lip slightly concave, and claw-like contraction at base; Stamens 4, strong enemy. Nutlets are rectangular, triangular and have small points. The flowering and fruiting period is from June to September.