桃仁为蔷颔科植物桃Prunuspetsica（I。）Batch和山桃prunusdavidiana（Cars．）Franch．的干燥成熟种子。药用水蝉除去种皮，俗称光桃仁。作者近日发现一批劣质光桃仁，其原植物确系桃，但外表与正品有较明显区别。正品：表面光滑而光泽，质脆，富油性，维管束痕迹不甚明显， Peach kernel is Prunus petsica (I.) Batch and Prunus davidiana (Cars.) Franch. Dry ripe seeds. Medicinal leech removes seed coat, commonly known as light peach kernel. The author recently discovered a group of inferior light peach kernels, whose original plants were indeed peaches, but the appearance and the genuine products were obviously different. Authentic: The surface is smooth and luster, crisp, rich in oil, and the vascular bundle marks are not obvious.