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Bai Zhu (Atractylodis Macrocephalae Rhizoma) from Jingmen Jun
Bai Zhu (Atractylodis Macrocephalae Rhizoma) from Shizhou

Taste: bitter, sweet, pungent. Nature: warm. The flavor is dense while the qi is light; it can ascend and descend, belonging to yin within yang. Non-toxic. Zhejiang Bai Zhu (commonly called Yun Tou Shu). Grown in flat, fertile land, the rhizomes are quite plump due to nourishment by manure and irrigation; Shexian Bai Zhu (commonly called Gou Tou Shu), produced in deep valleys, though slender and small, is full of earthy qi. (Those produced in Ningguo, Chizhou, and Changhua are similar to those from Shexian because their borders are adjacent.) Harvesting of roots occurs in autumn for both, but processing methods differ. Zhejiang varieties are large chunks roasted while rotating, becoming oily after each moistening; Shexian varieties are sliced thin and quickly dried, resulting in extreme dryness and whiteness. In usage, whiteness indicates superiority, and Shexian origin is particularly excellent. Before use, chew and moisten with human milk to moderate its nature; then stir-fry with soil from old walls to borrow its qi. (Select soil from east-facing old walls, grind fine, stir-fry with Bai Zhu until brown, sieve out the soil. This is done because Spleen Earth is injured, so true earth qi is borrowed to supplement it. If not a Spleen disease, this processing need not be strictly followed.) Enters the Heart, Spleen, Stomach, and San Jiao meridians. Must be guided by Fang Feng (Saposhnikoviae Radix) and Di Yu (Sanguisorbae Radix). Removes dampness and benefits dryness, soothes the Spleen and generates fluids. Drives out food stagnation and phlegm-saliva in the epigastrium, eliminates edema and distension in the umbilical and abdominal regions. Stops vomiting, regurgitation, and cholera-like symptoms, tonifies fatigue and internal injury. For laziness in moving hands and feet and excessive sleepiness, increased dosage is beneficial; for aversion to eating and fever, doubled dosage is appropriate. It has special efficacy for intermittent malaria (Jian Fa Nue, occurring every other day) and immediate effect for sudden profuse watery diarrhea (Cu Bao Zhu Xie). Alternatively, processed by four methods and ground into powder to arrest sweating (from Li Dongyuan's formula), or used as a single ingredient made into pills with congee to regulate the Spleen (from Zhu Danxi's formula). Decoctions are contraindicated for Ben Tun accumulation because it often causes Qi closure; carbuncles and sores are forbidden because it promotes pus generation. Treats wind in the skin and hair, benefits blood in the waist and navel. Thus, it stops at the exterior (skin/hair), penetrates to the middle (chest/heart), and descends to the lower (waist/navel). In the Qi level, it governs Qi; in the Blood level, it governs Blood. When there is no sweat, it induces sweating; when there is sweat, it stops it. Its function is similar to Huang Qi (Astragali Radix). Combined with Zhi Shi (Aurantii Fructus Immaturus), it forms a formula to dissipate痞 (fullness); assisting Huang Qin (Scutellariae Radix), it becomes a formula to calm the fetus. Misuse in asthma cases leads to unbearable congestion and obstruction. Another variety with pale skin is named Cang Zhu (Atractylodis Rhizoma). Originating from Maoshan (belonging to Jurong County, Zhili), it is of the first quality; selecting clean and solid pieces is best. Scrape off the coarse skin, soak in rice wash water, and stir-fry until dry. (Soak in rice wash water for one shichen [approx. 2 hours], slice, and stir-fry dry.] Also guided by Fang Feng and Di Yu, enters the Foot Yangming and Taiyin meridians. Eliminates phlegm nodules and sacs, removes tightness in the chest. Treats severe wind affecting the body and face, and wind-dizziness headache very swiftly; wards off mountain miasma and epidemic seasonal pathogens especially effectively. Warms the Stomach and calms the fetus, broadens the middle and promotes appetite. Drives away mass formations, stops pain from heart and abdominal distension. Because its qi is pungent, strong, and penetrating, it induces sweating to remove dampness from the Upper Jiao, making its efficacy optimal. However, if used to tonify the Middle Jiao and remove dampness, its strength is far inferior to Bai Zhu. Still decocted together with Huang Bo (Phellodendri Cortex) (i.e., Er Miao San), it vigorously clears damp-heat from the Lower Jiao. The *Shennong Classic* states: "If you wish for long life, you should consume Shan Jing." This refers to this herb. The taboos for both types of Zhu include sparrow meat, clams, plums, and peaches.

(Commentary:) Although there are two types of Zhu, their functions in tonifying the Spleen and drying dampness are identical. However, Bai Zhu has more tonifying properties and possesses the ability to arrest sweating; Cang Zhu has more therapeutic/draining properties and specializes in inducing sweating. In any prescription, they cannot be used interchangeably. Yet, since Bai Zhu is drying, why does the *Ben Jing* state it generates fluids? This is because the Spleen dislikes dampness. When Spleen dampness prevails, Qi cannot transform and distribute, so how can fluids be generated? Therefore, it is said that the Bladder is the mansion of fluids, and Qi transformation arises from it. Now, using Bai Zhu to dry the dampness allows Qi to circulate freely, and fluids are subsequently generated through Qi transformation. Similarly, Fu Ling (Poria) is also a drug that leaches out dampness; saying it generates fluids follows the same logic.