Astragalus is the dried root of the leguminous plant Astragalusmembranaceus (Fisch.) Bge.var.mongholicus (Bge.) Hsiao. Excavate in spring and autumn, remove fibrous roots and root heads, and dry in the sun. Astragalus is cylindrical, sometimes branched, with a thick upper end, 30-90cm long and 1-3.5cm in diameter. The surface is light brown or light tan, with irregular longitudinal wrinkles or grooves. It is hard and tough, not easy to break, the cross-section is fibrous and powdery, the bark is yellow-white, the wood is light yellow, there are radial textures and fissures, and the center of the old roots is occasionally rotten, dark brown or hollow. The smell is slight, the taste is slightly sweet, and there is a beany smell when chewed.