Hello. Herb base source is the root of the leguminous herb Astragalus mongolia, Astragalus membranaceus. Herb identification astragalus taproot cylindrical, some have branches, the upper end of the thicker, 30 ~ 90 cm long, 1 ~ 3.5 cm in diameter, the surface of the longitudinal wrinkled color light brownish yellow or light brown, there are untidy longitudinal wrinkles or longitudinal grooves of the texture, hard and tough with powdery, the skin part of the yellow-white laxer; wood part of the chrysanthemum texture, the gas is like a bean taste slightly sweet. The old root center is occasionally withered and rotten, black-brown or hollow. Gas slightly, taste slightly sweet, chewing slightly soybean flavor. The quality of the root thick and long, chrysanthemum heart distinct, hollow small, less broken skin is good; red astragalus to skin color red, root uniform, solid, powdery enough is good. Specifications are generally divided into three grades according to thickness and length.