1, lock yang dry whole grass, flat cylindrical or slightly thin at one end, 8 to 21 cm long, 2 to 5 cm in diameter. surface reddish brown to dark brown, wrinkled uneven, forming thick longitudinal grooves or irregular depressions, sometimes visible triangular scales, and some inflorescences exist.

2, the texture is hard, not easy to break, the section is slightly granular, brown and soft. The odor is slightly fragrant, and the taste is slightly bitter and astringent.

3, lock yang slice for horizontal or oblique cut into the thick about 1cm or so of the segment, often with a rope through the string. To a fat, color red, solid, broken flour, do not show tendons and veins for the best.