Chinese Name Duzhong Latin Cortex Eucommiae English Name Eucommia Bark Key Characteristics Herb that tonifies yang. Source Dried stem bark of Eucommia ulmoides Oliv. Property, Flavor and Meridians Entered Sweet, warm; Liver, Kidney Actions To reinforce the liver and the kidney, strengthen the tendons and bones, and prevent miscarriage Indications Deficiency in the kidney marked by lower back pain and lack of strength,  threatened miscarriage, in addition, used for hypertension Precaution Use with caution in those with heat from yin deficiency. Chemical Composition It contains guttapercha, eucommioside, aucubin, etc.