青黛为爵床科植物马蓝、豆科植物木蓝、蓼科植物蓼蓝、十字花科植物菘蓝和草大青的叶或茎叶经加工制成的干燥粉末。具有清热解毒、凉血的功能,常用于温病发热,发斑发疹,咯血,腮腺炎,口疮,湿疹,黄水疮,丹毒等。在临床上青黛的用法有入丸剂、散剂、汤剂。《中药大辞典》亦谓:“内服煎汤,或 Barley is a dried powder made by processing the leaves or stems and leaves of Amaranthus majus, Malus amygdalus, Amaranthus indica, Indigo of cruciferae, and Leaves of acacia. It has the functions of clearing heat, detoxifying, and cooling blood. It is commonly used for fever, spotted rash, hemoptysis, mumps, aphthous ulcers, eczema, yellow water sores, and erysipelas. There are pills, powders, and decoctions used in clinical practice. The Dictionary of Chinese Medicine also says: "Internal decoction, or