Excerpted from  Bensky: Chinese Herbal Medicine Materia Medica, 3rd ed.

• Releases the exterior and dispels wind:  for exterior patterns of either wind-cold or wind-heat (depending on the herbs with which it is combined).  Also for carbuncles or boils when they first erupt, especially when accompanied by chills and fever.*
• Vents rashes and alleviates itching:  for the intital stage of measles and pruritis skin eruptions.*
• Stops bleeding:  as an auxiliary herb for hemorrhage, e.g., blood in the stool or uterine bleeding.  Best used charred for this action, as in Sophora Japonica Flower Powder (huai hua san).*