(1) Cross section of this specimen: One layer of epidermal cells covered by a thick cuticle, some with cork cells. Fibers and stone cells are scattered throughout the cortex. The vascular bundle sheath fibers form a crescent shape, often with 2–5 layers of stone cells on the inner side that extend tangentially to connect with stone cell clusters in the rays, forming a ring.Vascular bundles are exarch. Phloem rays gradually widen outward, displaying conical or branched stone cells. Phloem cells are mostly degenerate, with some bearing 1–3 scattered fibers laterally and several rows of parenchyma cells medially. Xylem vessels occur singly or in tangentially connected groups. Medullary cells have slightly thickened walls with distinct pits.Parenchymatous cells contain starch grains and calcium oxalate needles. Powder is yellowish-brown or grayish-brown. Epidermal cells are yellow or yellowish-brown, appearing nearly circular or oblong in cross-section with diameters of 24–78 μm, covered by a cuticle. Stone cells are pale yellow or yellow, appearing nearly square, fusiform, elliptical, or irregular in shape, with thick walls and distinct pore canals.Cortical fibers are pale yellow or yellow, 27–70 μm in diameter, with extremely thick walls and narrow cavities. Fine calcium oxalate needles are present within parenchyma cells.Separately, prepare a reference solution of clematine by dissolving the reference substance in ethanol to a concentration of 1 mg/mL. Perform thin-layer chromatography (Appendix ⅥB). Apply 5 μL of each solution onto the same silica gel G plate prepared with 2% sodium hydroxide solution. Develop with a mobile phase of toluene-ethyl acetate-methanol-water (2:4:2:1) solution cooled below 10°C as the developing solvent. Remove, air-dry, and spray successively with potassium bismuth iodide solution and sodium nitrite ethanol solution. In the chromatogram of the test sample, spots of the same color as those in the reference standard chromatogram should appear at corresponding positions.