Indigo Naturalis. Part used: Leaf. Known as Indigo. Entering meridians: Liver, Lung and Stomach. Qing Dai clears heat, resolves fire toxicity, cools the blood, reduces maculae, disperses stagnation, reduces swelling, drains liver fire, dispels summerheat, extinguishes wind to stop tremors, drains lung heat and cools the blood. All Phoenix Medical dry authentic herbs and concentrated herbal granules are free of sulphur, herbicides and pesticides.