[Formation and differentiation of the famous coptis regions].

From the Tang Dynasty, Xuanzhou has been considered as the famous area of genuine regional coptis as its production of high-quality. Till the Ming Dynasty, coptis resource in Xuanzhou was exhausted, and weilian, yalian (coptis produced in two districts in Sichuan) and yunlian (coptis produced in Yunnan) became famous-region coptis, three varieties of coptis coming from three districts. During the formation of new famous regions, species variation, geographical environment, historical background, cultivation technique and social economy played a role. For example, xuanlian became famous for doctors in Xinan area loved to use it to a large extent. And cultivation technique was the key point for weilian to become the famous-region herb. Now with the shrinking of planting area, yalian could be hardly considered as famous-region copitis and yunlian has withdrawn from commodity for its high cost and low production.