Sheng Di Huang (Raw Rehmannia Root)

Official Di Huang is the fresh or dried tuber of Rehmannia glutinosa. The pharmacopoeial name is Rehmanniae Radix. The fresh tuber is Xian Di Huang; slowly baked to about eight-tenths dry is Sheng Di Huang (Gan Di Huang). Huaiqing, Henan lots are habitually called Huai Di Huang. Shu Di Huang is a separate article: steamed or wine-stewed until black and moist, sweet and slightly warm, supplements Blood, enriches Yin and fills essence and marrow—the cold heat-clearing action is gone. Write Sheng Di Huang; do not dispense Shu Di. Acute cooling of Blood and stopping bleed may name Xian Di Huang.

According to the Chinese Pharmacopoeia, Sheng Di Huang is sweet and cold, enters the Heart, Liver and Kidney channels, and acts to clear heat and cool the Blood, nourish Yin and generate fluid. It is used for heat entering construction-blood, warm-toxin macular eruption, vomiting and nosebleed, heat disease injuring Yin, crimson tongue and vexing thirst, fluid damage with constipation, Yin-vacuity fever, steaming bone taxation heat, and interior-heat wasting-thirst. Fresh Rehmannia is sweet-bitter-cold: more urgent to clear heat, generate fluid, cool Blood and stop bleed. Sweet-cold and moistening, it suits heat exuberance injuring Yin, not Spleen vacuity with damp stagnation, loose stool and bloating.

Warm disease at construction-blood, vomiting of blood, nosebleed and sore throat more often use Xian Di Huang (12–30 g). Yin-vacuity interior heat, fluid-damage constipation, steaming bone and wasting-thirst more often use Sheng Di Huang. Blood-vacuity sallow complexion, Liver-Kidney essence depletion and premature greying use Shu Di Huang—not this article. Cut thick slices; being moist it may be added later or cooked longer. Do not mix raw and prepared.