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(Refers to selecting solid-quality dried raw Rehmanniae Radix. Boil small amounts of fresh Rehmanniae Radix in aged yellow wine to extract the juice, then re-immerse the dried Rehmanniae Radix into this juice. After nine cycles of steaming and sun-drying, until its texture becomes soft and moist, this is prepared Rehmanniae Radix [Shu Dihuang].)

[Flavor and Properties]
Sweet, slightly bitter, slightly warm. It belongs to "Yin within Yang." Its nature is sinking (descending). It enters the channels of the Hand and Foot Shaoyin (Kidney/Heart) and Jueyin (Liver/Pericardium).

[Indications]
Tonifies Kidney Water and True Yin. Harmonizes blood and Qi postpartum. Relieves acute pain in the umbilical and abdominal regions. Nourishes Yin to subdue Yang. Strengthens the source of Water (Kidney). In Zhang Zhongjing's Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia), it serves as the chief among all herbs; it is the source generated by Tianyi (Heavenly One/Water). In the Tangye (Decoctions) formula Siwu Tang (Four Substance Decoction), used for treating organs that store blood, it serves as the Jun (Emperor) herb, reflecting that Gui Water (Kidney) and Yi Wood (Liver) share a unified therapeutic approach. It is also stated that Raw Rehmanniae Radix generates Essence and Blood; using Asparagi Radix (Tianmendong) can guide it to the site of generation. Prepared Rehmanniae Radix tonifies Essence and Blood; using Ophiopogonis Radix (Mendong) can guide it to the site of tonification. Contraindications: Radish, Scallion, various blood products, Garlic.

[Flavor and Properties]
Bitter, neutral, non-toxic. Its action ascends but slightly descends. It belongs to "Yang within Yin." It is the principal herb for the Hand and Foot Taiyin (Lung/Spleen) channels. It also enters the Blood aspect of the Liver and Spleen.

[Indications]
Calms the Spleen channel. Treats abdominal pain. Secures Stomach Qi. Stops diarrhea and dysentery. Harmonizes blood vessels. When used with Atractylodis Macrocephalae Rhizoma (Baizhu), it tonifies the Spleen. When used with Chuanxiong Rhizoma (Chuanxiong), it tonifies the Liver. When used with Ginseng Radix et Rhizoma (Renshen) and Atractylodis Macrocephalae Rhizoma (Baizhu), it tonifies Qi. When used with Saposhnikoviae Radix (Fangfeng), it promotes the eruption of smallpox/rashes. When used with Zingiberis Rhizoma Recens (Jiang) and Jujubae Fructus (Dazao), it warms the channels and disperses dampness. Stir-fried with wine, it tonifies Yin. Used raw, it treats tenesmus. (White-colored Paeoniae Radix reflects the image of the West; it can drain water within Earth to benefit the Spleen. Red-colored Paeoniae Radix reflects the image of the South; it can move stasis in the blood to disperse pathogens.)

Merely stating that Paeoniae Radix can relieve central tension seems contradictory due to its sour and astringent, converging flavor. However, by restraining the Liver, it regulates the blood. Once the blood is regulated, the center naturally harmonizes. It is also said that Bai Shao (White Peony Root) is often used in treating Shanghan (Cold Damage) because it governs chills and fever and promotes urination. Although its sour and astringent nature suggests retention, why does the *Ben Jing* (Divine Farmer's Materia Medica) state otherwise? This is because it benefits Yin, nourishes dampness, and retains body fluids; thus, Metal generates Water, and urination becomes free-flowing naturally, not because the herb itself has a diuretic property.