Herbs that Clear Heat and Dry Dampness

In clearing heat, what is Qin Pi's (fraxini cortex's) specialty?

Qin Pi clears damp-heat, and it is also astringent to bind the intestines, making it ideal for treating diarrhea and dysentery.

Source: Bensky, D. (2004). Chinese Herbal Medicine: Materia Medica. Seattle, WA: Eastland Press. pp. 147 [Q397]