Red wheel pattern. Caulis Sargentodoxae and Caulis Spatholobi are easily confused. The section of Caulis Sargentodoxae has red wheel lines, and the section of Caulis Spatholobi has eccentric semi-rings. Medulla tetrapanacis and medulla tetrapanacis are easily confused, and there are hollow parts and solid parts. Sargentodoxa belongs to Sargentodoxa. Deciduous woody vines, up to 10 m. The vine is 9 cm in diameter and the whole plant is hairless; When the branches are dark red, the old bark sometimes splits vertically.