Tangerine red, known as tangerine red in Chinese literature, is a plant that can be used as medicine after being dried in the sun or in the shade, and the medicinal part of tangerine red is the dried outer layer of the plant's pericarp. Tangerine red mainly grows in Fujian, Zhejiang, Hunan, Guangdong, Guangxi, Guizhou and other regions, tangerine red is presented as a long strip or irregular sheet state, its surface is yellowish brown or orange-red.