(1) rabbit ear grass whole grass length 10-20cm. The rhizome leaves are cylindrical, slightly curved, with tight internodes, shaped like a silkworm body, 2- 10cm long, 3-6mm in diameter, and the surface is dark brown or purple brown; Brittle, easily broken, grayish yellow or brown in cross section, with 3-7 white punctate vascular bundles arranged in a ring. The root is attached to the rhizome, with a length of 3-9cm, a diameter of about 0.2cm and a dark brown surface. The upper stem and leaf have withered, and the stem diameter is 0. 1-0.2cm, brown; Basal leaves have long stems and many leaves are curled and broken. After flattening, the complete leaves are oval, 3-5cm long and 2-3cm wide. The apex is acute, the base is broadly wedge-shaped, and the edge is sparsely serrated, gray-green or yellow-green; Veins are purplish on the back. Spike terminal, 2-8 cm long; Bracts are leaflike, with small flowers, lavender or deep purple; Calyx spatulate, with 2 shallow teeth; Corolla tube is curved, and the upper part is lipped. Slight gas and bitter taste.

(2) rabbit ear grass's basal leaves are broadly cuneate at the base, with nearly entire edges or small shallow teeth.

(3) The short tube rabbit ear grass is 5- 15cm long and the stem is purplish red. Cauline leaves are round or oval, the apex is blunt, the middle edge is crenate, and the base is wedge-shaped. Inflorescence 2-6 cm long, with purple flowers; The calyx is bract-shaped, and the top is slightly concave.

There are many leaves, and purple in green is better. Surface view of Leymus chinensis leaves: the cell wall of upper epidermis is relatively flat; The cell wall of the lower epidermis is curved, some vertical walls have protrusions, and there are many pores in the upper and lower epidermis, and the pores are uncertain.

Cross section of rabbit ear grass stem with large calyx: 1 epidermal cells, small square block; Cortical cells are round, irregularly arranged and have intercellular spaces; The endodermis is 1 row of square cells, arranged neatly, with 2-5 rows of stele sheath fibers, and is not lignified. The phloem is narrow and ring-shaped; Outside the xylem, there are wood fiber bundles arranged in a ring, and inside there are non-lignified cell groups with thick cell walls, which are arranged at intervals of 1 wheel; The catheter is located inside the wood fiber. The number of parenchyma cells in medulla; Most of the central part is hollow.

Cross-section of the root-like stem of rabbit ear: 1 expels epidermal cells, and the cell wall is reddish brown; The cortex is broad and the cells are round; The endodermis is 1 row of cells, fine; There are 5 vascular bundles, the phloem is narrow, and the xylem is composed of vessels and wood parenchyma cells. The center is the essence. 1. Take 5g(20 meshes) of this product powder, add 50ml of ethanol, and extract in water bath for 30min. After the extract passed through 10g alumina column, it was eluted with 20ml ethanol, and the eluent was concentrated to 10ml under reduced pressure, and then 10ml water was added, shaken with 50ml petroleum ether for 5min, and the water layer was separated, and then added.

1. 1. Take 1ml water extract, add 2-3 drops of 5%α- naphthol ethanol solution, shake well, and slowly add 1ml concentrated sulfuric acid along the test tube wall. A purple ring appears at the interface between the two solutions (check sugar).

1.2. Take 1ml n-butanol extract, add Godin reagent (1% vanillin ethanol solution and 3% perchloric acid solution, and mix them equally when using) to make it reddish purple, or take 1 drop phloroglucinol reagent and hydrochloric acid, put it in an evaporating dish, and add a few drops of n-butanol extract to make it reddish purple.

2. Thin-layer chromatography: take 1 n-butanol extract as the test solution, and add catalpol standard solution with the concentration of 1mg/ml, respectively absorb the test solution and the reference solution and spot them on a silica gel G plate, and use n-butanol-ethyl acetate-glacial acetic acid (10: 9: 1). After spraying Godin reagent, it is baked at 80-90℃ for 3-4 minutes to develop color, and spots of the same color appear in the chromatogram of the test sample at the position corresponding to the chromatogram of the control sample.