Huanglian is a commonly used medicinal herb for clearing heat and drying dampness. It consists of the dried rhizomes of Coptis chinensis Franch., Coptis deltoidea C.Y. Cheng et Hsiao, or Coptis teeta Wall.—all belonging to the genus Coptis in the Ranunculaceae family. These three species are commonly known as “Weilian,” “Yilian,” and “Yunlian,” respectively.Weilian and Yalian are primarily produced in Sichuan and Hubei. Yunlian is primarily produced in Yunnan. It has the effects of clearing heat, drying dampness, purging fire, and detoxifying.When taken internally, it is used to treat damp-heat-induced fullness and distension, vomiting and regurgitation of acid, diarrhea and dysentery, jaundice, high fever with mental confusion, excessive heart fire, restlessness and insomnia, palpitations, blood-heat-induced vomiting and nosebleeds, red eyes, toothache, diabetes, and abscesses, boils, and carbuncles;When applied topically, it can treat eczema, damp sores, and purulent discharge from the ear canal.