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This is the *Tangdi* (Choi tree) mentioned in the *Erya*. It grows everywhere in the mountains and fields. The tree is five to six chi tall. Its leaves, flowers, and trunk resemble those of the large plum (*Prunus salicina*), except that its fruit is small, like a cherry. When ripe, it is red. It tastes sweet and sour with a fragrance, having a slight astringency.

Its taste is sour, bitter, and pungent. Its nature is neutral. Its medicinal property is moistening and descending. It belongs to "Yin within Yang." It is a herb entering the Qi aspect of the Spleen meridian. It further enters the Hand-Yangming Large Intestine meridian and the Foot-Taiyang Bladder meridian. Its main indications are resolving blood stasis, moistening dryness, draining stagnant Qi, breaking up accumulations and masses, treating constipation due to Qi stagnation and dryness in the Large Intestine with sluggish obstruction, relieving acute pain in the five Zang organs and the Bladder, treating cold pus in the waist and hips, directing Qi downward, promoting urination, and managing abdominal edema as well as edema of the four limbs and face.

Case Record A woman became ill due to palpitations. After recovery, she suffered from insomnia with her eyes open. Qian Zhongyang instructed her to drink decoction made with *Yuliren* (Prunus japonica Seed) and wine until intoxicated, after which she recovered. This is because the visual system connects internally to the Liver and Gallbladder; fear causes Qi stagnation, leading to rebellious Gallbladder Qi that fails to descend. *Yuliren* can remove stagnation. Accompanied by wine entering the Gallbladder channel, once the stagnation is resolved, the Gallbladder Qi descends, allowing the eyes to close for sleep. Combined with Danggui (Angelicae Sinensis Radix), Dihuang (Rehmanniae Radix), Maren (Cannabis Fructus), Taoren (Persicae Semen), Maidong (Ophiopogonis Tuber), raw honey, and Rousongrong (Cistanches Herba), it treats severe constipation due to dryness and obstruction. In severe cases, Dahuang (Rhei Radix et Rhizoma) is added.

[Discussion] The diuretic effect of *Yuliren* (Prunus japonica Seed) stems from its ability to dissipate stagnant Qi. Water is transformed from Qi. Qi belongs to Yang and is active; when activity leads to stagnation, it falls under Yin. The origin of Qi indeed arises from "Yang within Yin," but Qi stagnation occurs due to "Yin within Yang" (obstruction of Yang by Yin pathogens). Once the stagnation is dispersed, Yang transforms, and water flows. Therefore, Jiegu (Zhang Yuansu) refers to it as a herb for the Qi aspect of the Spleen meridian. The *Shennong Bencao Jing* uses it to treat abdominal edema and edema of the face, eyes, and four limbs. Spleen Earth carries the Yang energy emerging from the earth and ascends, distributing Middle Qi to govern Blood. Thus, all five Zang organs possess Yin Qi, with the Spleen acting as the pivot. The therapeutic effects of *Yuliren* largely cover the functions governed by Spleen Qi. Consequently, Jiegu's claim regarding breaking blood does not equate to other herbs. The so-called "moistening dryness" is achieved by venting Yin stagnation to transform Blood. Since Blood stagnation leads to Qi dryness, transforming Blood harmonizes Ying and Wei, thereby moistening dryness. Moreover, its function of dissipating stagnation is not limited to promoting water metabolism. Conditions where emotional stagnation damages Yin and subsequently obstructs Yang can be treated by analogy based on this principle (as seen in Qian's treatment of insomnia). Miao states that its nature is specifically descending, effectively guiding out Large Intestine dryness and promoting fluid metabolism throughout the body. However, its use often depletes Body Fluids, worsening dryness and constipation. It is a herb for treating symptoms and emergency relief. Those with insufficient Body Fluids should avoid using it lightly.

[Processing] Soak first in hot water, remove the skin and tips. Then soak in raw honey overnight, drain, and dry in the shade. Grind into a paste for use.