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Rehmanniae Radix from Jizhou

Rehmanniae Radix from Yizhou

Also known as.

Taste: Bitter, Sweet. Nature: Cold. Qi is thin and flavor is strong; it sinks and belongs to Yin, specifically Yang within Yin. Non-toxic. In late autumn, when the juice descends, the roots are harvested and solidified. Sun-dried ones have a neutral nature; fire-dried ones have a warm nature. Steamed and dried ones have warming and tonifying effects; raw-dried ones have neutral and dispersing effects. Due to differences in production areas between north and south, the potency varies greatly. Those planted in Jiangsu and Zhejiang (mostly grown in fertile soil) are influenced by the Yang Qi of the south; although their texture is smooth and moist, their medicinal power is weak. Those produced in Huaiqing Prefecture (a commandery name belonging to Henan) (mostly growing in deep valleys) inherit the pure Yin of the north; their skin has bumps and their power is strong. Using the "inch-water" test method, three grades can be distinguished: those floating on the water surface are Tianhuang (Heavenly Rehmannia); those sinking to the bottom are Dihuang (Earthly Rehmannia); those half-floating and half-sinking are Renhuang (Human Rehmannia). Only Dihuang is superior and suitable for use; the other two are inferior and should be discarded. It fears *Elaeagnus umbellata* (Wuyi), detests *Fritillaria thunbergii* (Beimu), and taboos "Sanbai" (Three Whites). Chewing while contacting iron vessels may cause Shenxiao disease (Kidney Wasting-Thirst) (cut with bamboo knife). Consuming it together with radish may cause hair whitening. Combined with *Ophiopogon japonicus* (Maidong), it serves well as a guiding agent; stir-fried with ginger juice, it prevents phlegm stagnation in the chest and diaphragm. (For those who consume alcohol, this herb must be processed according to these methods, as alcohol-induced diseases often involve phlegm, and there is fear of stagnation causing chest fullness.) If used to reach the upper body to tonify brain marrow deficiency, or to act externally to moisturize dry skin, it must be soaked in wine to promote rapid efficacy. It enters the Hand-Shaoyin Heart Meridian and Hand-Taiyang Small Intestine Meridian.

It cools Heart Fire and Blood Heat, allowing eye sores to heal; it drains Damp-Heat from Spleen Earth, enabling muscle growth. Bone-steaming consumptive fever can be retreated; five-palm heat can be driven away. It is a single-prescription remedy for stopping bleeding, vomiting blood, and epistaxis, and an essential medicine for treating trauma and metal wounds.

It also treats amenorrhea in women, and postpartum blood attacking the heart. For pregnancy-related bleeding and threatened abortion, or metrorrhagia with continuous bleeding: if the patient's pulse is surging and indicates excessive heat, adding it poses no harm; however, if there is Cold in the Spleen and Stomach, careful consideration is required. Its flower is named Disui (Earth Marrow); taking it can prolong life; its seeds ground and mixed with water have efficacy equal to the root. Wine-moistened and steamed until black, it is named Shudihuang (Prepared Rehmannia Root).

Nature: Slightly Warm. It slightly dispels Cold and enters the Foot-Shaoyin Kidney Meridian and Hand-Foot-Jueyin Liver Pericardium Meridians. It greatly tonifies Blood deficiency and doubles nourishes Kidney Water. It increases Qi strength, brightens eyes and ears, fills bone marrow, and benefits True Yin. For post-typhoid leg and thigh pain, it shows special merit; for acute abdominal pain after recent childbirth, it produces immediate effect. It darkens beard and hair, enhances complexion, and preserves youth. Zhang Zhongjing formulated Ba Wei Wan (Eight-Ingredient Pill) using it as the Sovereign drug, drawing from the source of all things born under heaven, specifically to tonify Yuan Qi in the Kidney; (Heaven generates One with Water, so human Yuan Qi is governed by the Kidney). Li Dongyuan established Si Wu Tang (Four Substance Decoction) as the Principal formula, evolving the treatment where Gui Water (Kidney) and Yi Wood (Liver) return to one therapy, simultaneously treating the meridian storing Blood. (Gui Water belongs to the Kidney, Yi Wood belongs to the Liver; the Liver is the Sea of Blood, hence it is called the meridian storing Blood.) Long-term consumption brightens the eyes and extends longevity.

(Chen Jiamo) Commentary: Zhu Danxi said: "Tonifying Blood for Qi diseases causes no harm even if not perfectly indicated." Reading this raises doubts. Among blood-tonifying herbs, none surpass *Rehmanniae Radix* (Dihuang) and *Angelicae Sinensis Radix* (Danggui). If taken in excess, their cloying nature often damages Stomach Qi. I have seen patients with deficient Stomach and weak Qi, unable to circulate, suffering from bleeding from upper orifices. Using this herb to form Si Wu Tang (Four Substance Decoction) as a cooling and blood-tonifying prescription, and administering it frequently for regulation, instead caused chest and diaphragm stuffiness, reduced appetite, vomiting and diarrhea, asthma, hematemesis, worsening daily towards death. This is precisely because blood-tonifying herbs damaged the harmonious Stomach Qi; how can one say it is harmless?

Generally, while Blood deficiency should not be treated solely by tonifying Qi, Qi deficiency should not be over-treated by tonifying Blood. The value lies in accurate syndrome differentiation and appropriate adjuvant assistance, thereby avoiding bias and damage.