形似菖蒲而柔润。叶至难死。掘出复生。须枯燥乃止。（即此可知为至阴之味）二
八月采根。曝干用。
根气寒味甘。大苦兼辛。气味俱浓。沉而降。阴也。又云。阴中微阳。肾经本叶。入足
阳明手太阴经气分。本经主消渴热中。除邪热。肢体浮肿下水。补不足益气。诸本草泻膀胱
热。肾之邪火有余。滋肾阴。除肺热。疗肾虚火炎肺嗽。或心烦躁闷。并治足阳明火热。伤
寒久疟。烦热及骨。热劳往来。肾气劳损。憎寒虚烦。又安胎。止子烦。并产后蓐劳。久服
泄。方书治喘淋口病。中风伤暑。发热呕吐。头痛腰痛。小便不通。伤燥热厥。呃逆嗖血。
身体痛痹。痿厥香港脚。螈 烦悸。盗汗不得卧。怠惰嗜卧不能食。遗精诸证。知母禀天一水
德。体用具备。故主濡润燥渴。对待热中。其润下水道者。缘水得母气。母气之脏真高于肺。
以行营卫阴阳。乃能游溢通调转输决渍耳。（之颐）知母其用有四。泻无根之肾火。疗有汗
之骨蒸。止虚劳之热。滋化源之阴。仲景用入白虎。治不得眠者。烦躁也。烦出于肺。躁出
于肾。故君以石膏。佐以知母。清肾之源。缓以粳甘。使不速下也。凡病小便闭塞而渴者。
热在上焦气分。宜清肺中伏热。用气味俱薄之药以滋化源。若热在下焦血分而不渴者。宜滋
真水。使阴气行而阳自化。用黄柏知母是也。（东垣）知母下润肾燥而滋阴。上清肺金而泻
火。乃二经气分药。黄柏则是肾经血分药。故二药必相须而行。（濒湖）与茯苓同用。清下
焦热。与黄芩同用。清上焦热。（希周） 入白虎汤。解伤寒阳明证。口渴头疼。烦热。鼻
干不得眠。加竹叶麦冬。名竹叶石膏汤。治阳明经前证。大渴饮引头疼欲破。因作劳而得者。
加人参。名人参白虎汤。汗后烦热不解。亦用之。同麦冬石膏贝母橘红鳖甲青蒿牛膝。治久
疟烦热而渴。同贝母天冬麦冬沙参甘草桑白皮枇杷叶五味子百部。治阴虚咳嗽。同黄柏车前
木通
附方 久近痰嗽。自胸膈下塞停饮。至于脏腑。用知母贝母各一两。为末。巴豆三十枚。
去油。研匀。每服一字。用姜三片。二面蘸药。细嚼咽下。便睡。次早必泻一行。其嗽立止。
壮人乃用之。（一方不用巴豆）久嗽气急。知母去毛切五钱。隔纸炒。杏仁五钱。姜水泡去
皮尖焙。以水一钟半。煎一钟。食远温服。次以萝卜子杏仁。等分为末。米糊丸。服五十丸。
姜汤下。以绝命根。
〔论〕知母苦寒相合。固为肾剂。第其味甘而苦。苦复兼辛。虽苦居其胜。然以甘始而
以辛终。不谓之入肺胃气分不可也。（四月花则气畅于火。八月实则气孕于金。）本经谓其补
不足益气。乃从除邪气肢体浮肿下水来。厥有深旨。经曰。三焦者中渎之府。水道出焉。属
膀胱。是孤之府也。是六腑之所与合者。夫三焦相火。本气之元。乃属膀胱而行水化。膀胱
固属肾也。经又云。二阴至肺。其气归膀胱。外连脾胃合之。所谓饮入于胃。游溢输脾。脾
气散精。上归于肺。通调水道。下输膀胱。水精四布。五经并行。不即可明于除邪气肢体浮
肿之义乎。盖水化即气化也。兹味之功。由胃肺合而致其苦寒之用于上。即由肺胃合而达其
苦寒之化于下。故能泻膀胱热及肾之相火有余者。本经即下水以明其补不足益气。正以由阳
滋阴。即由阴存阳。与所言阴虚则无气。无气则死之旨合也。至如火炎肺嗽。消渴热中。心
烦躁闷。肾气劳损。热劳（患人虚而口干者加用之）骨蒸等病。皆因清热以致其益气之功。
不止于以寒对热而已。又伤寒久疟。有伤于后天气血。以累及先天。必借此金水滋生之味。
乃可胜邪热而还真阴。盖天一真阴。实后天生气之元。经所云益气者此耳。但苦寒性味。用
者当审所宜。勿致反损中土生气。而绝阴化于阳之本也。
缪氏曰。阳痿及易举易痿。脾弱不消。胃虚不纳。肾虚溏泄等证。法并禁用。
〔修治〕拣肥润裹白者。去毛切。上行用酒浸焙干。下行则盐水润焙。勿犯铁器。
The root resembles *Acorus tatarinowii* (Changpu, 菖蒲) but is soft and moist. The leaves are extremely difficult to kill; if dug up, they regenerate until they become completely dry. (From this, it can be known that it is a substance of extreme Yin nature.) The roots are harvested in the second or eighth lunar month and dried in the sun for use.
The root has a cold property and a sweet taste, with a strong bitter flavor accompanied by a pungent note. Its aroma and flavor are intense; its nature is sinking and descending, belonging to Yin. It is also said to contain slight Yang within Yin. It enters the Kidney meridian (Shen Jing, 肾经) and the Qi aspect of the Foot-Yangming Stomach meridian (Zu Yangming Wei Jing, 足阳明胃经) and Hand-Taiyin Lung meridian (Shou Taiyin Fei Jing, 手太阴肺经). The *Shennong Bencao Jing* indicates it treats Xiao Ke (Wasting-Thirst, 消渴) and Re Zhong (Heat in the Middle Jiao, 热中), eliminates pathogenic heat, reduces limb edema, promotes urination, tonifies deficiencies, and benefits Qi. Other materia medica texts state it clears Heat from the Bladder, clears Excess Fire from the Kidney, nourishes Kidney Yin, clears Lung Heat, and treats Lung cough due to Kidney deficiency with flaming fire, or mental restlessness and oppression. It also treats Heat-Fire of the Foot-Yangming meridian, chronic malaria from Cold Damage (Shang Han, 伤寒), Heat entering the bones, bone-steaming consumptive fever, Kidney Qi damage, aversion to cold with empty irritability, calms the fetus, stops fetal irritability, and treats postpartum consumption. Long-term use may cause diarrhea. Formulary books treat asthma, strangury, mouth diseases, wind-stroke with summerheat injury, fever with vomiting, headache and lumbar pain, urinary obstruction, heat exhaustion with cold extremities due to dryness-heat, hiccups, hemoptysis, body pain and bi-syndrome, flaccidity and cold extremities, Hong Kong leg (Jiaoqi, 香港脚/foot-qi), convulsions with irritability, night sweats with insomnia, lethargy with desire to lie down and inability to eat, spermatorrhea, and various other syndromes. Zhi Mu (Anemarrhenae Rhizoma, 知母) inherits the virtue of Tianyi Water (First Heaven Water, 天一水), possessing both substance and function; thus, it primarily moistens dryness and thirst, countering Heat in the Middle. Its ability to moisten the lower waterways stems from Water receiving the Qi of its Mother (Kidney); the True Qi of the Mother organ rises above the Lung, thereby circulating Ying and Wei Qi and Yin-Yang, enabling free flow and regulation, transportation, and drainage. (Zhi Yi) Zhi Mu has four main functions: clearing Rootless Kidney Fire, treating bone-steaming fever with sweating, stopping consumptive fever, and nourishing the Yin of the Source of Transformation (Hua Yuan, 化源). Zhang Zhongjing uses it in Bai Hu Tang (White Tiger Decoction, 白虎汤) for patients unable to sleep due to irritability. Irrability (Fan, 烦) originates from the Lung, while restlessness (Zao, 躁) originates from the Kidney; therefore, Shi Gao (Gypsum Fibrosum, 石膏) is used as the Sovereign herb, and Zhi Mu as the Assistant, to clear the source of the Kidney, while Yi Mi (Coicis Semen, 薏苡仁 - *Note: Text says Jing Mi, usually Coix Seed or Rice, here likely refers to Oryzae Sativa Arillus/Rice* 粳米) and Gan Cao (Glycyrrhizae Radix et Rhizoma, 甘草) are used to moderate the action so it does not descend too quickly. For cases of urinary retention accompanied by thirst, the Heat is in the Qi aspect of the Upper Jiao; one should clear latent Heat in the Lung using herbs with light aroma and flavor to nourish the Source of Transformation. If Heat is in the Blood aspect of the Lower Jiao without thirst, one should nourish True Water, allowing Yin Qi to circulate so Yang transforms naturally; Huang Bo (Phellodendri Cortex, 黄柏) and Zhi Mu are used. (Dong Yuan) Zhi Mu moistens Kidney dryness downward to nourish Yin, and clears Lung Metal upward to drain Fire; it acts on the Qi aspect of these two meridians. Huang Bo acts on the Blood aspect of the Kidney meridian; thus, these two herbs must be used together synergistically. (Bin Hu) Used with Fu Ling (Poria, 茯苓), it clears Lower Jiao Heat; used with Huang Qin (Scutellariae Radix, 黄芩), it clears Upper Jiao Heat. (Xi Zhou) Added to Bai Hu Tang, it resolves Yangming syndrome of Cold Damage, characterized by thirst, headache, irritability, dry nose, and insomnia. Adding Zhu Ye (Bambusae Folium, 竹叶) and Mai Dong (Ophiopogonis Radix, 麦冬) creates Zhu Ye Shi Gao Tang (Bamboo Leaf and Gypsum Decoction, 竹叶石膏汤) to treat the aforementioned Yangming meridian symptoms, including severe thirst with excessive drinking, splitting headache, caused by overexertion. Adding Ren Shen (Ginseng Radix, 人参) creates Ren Shen Bai Hu Tang (Ginseng White Tiger Decoction, 人参白虎汤), also used when irritability persists after sweating. Combined with Mai Dong, Shi Gao, Bei Mu (Fritillariae Bulbus, 贝母), Ju Hong (Citri Reticulatae Pericarpium, 橘红), Bie Jia (Testudinis Carapax et Plastrum, 鳖甲), Qing Hao (Artemisiae Annuae Herba, 青蒿), and Niu Xi (Achyranthis Bidentatae Radix, 牛膝), it treats chronic malaria with irritability and thirst. Combined with Bei Mu, Tian Dong (Asparagi Radix, 天冬), Mai Dong, Sha Shen (Glehniae Radix, 沙参), Gan Cao, Sang Bai Pi (Mori Cortex, 桑白皮), Pi Pa Ye (Loquat Leaf, 枇杷叶), Wu Wei Zi (Schisandrae Fructus, 五味子), and Bai Bu (Stemonae Radix, 百部), it treats Yin-deficiency cough.
Supplementary Formula: For chronic phlegm-cough with fluid retention obstructing from the chest and diaphragm down to the viscera, use Zhi Mu and Bei Mu, each 1 liang, powdered. Add 30 seeds of Ba Dou (Crotonis Fructus, 巴豆), de-oiled, and ground evenly. Take one "zi" (a small measure) per dose. Dip both sides of three slices of fresh ginger into the powder, chew thoroughly, and swallow. Then lie down to sleep. There will be one bowel movement the next morning, and the cough will stop immediately. Only use for robust individuals. (One formula omits Ba Dou). For chronic cough with shortness of breath, take 5 qian of Zhi Mu, remove hairs and slice, stir-fry between paper. Take 5 qian of Xing Ren (Prunus Armeniacae Semen Amarum, 杏仁), soak in ginger water, remove skin and tips, and bake. Decoct in 1.5 zhong of water until 1 zhong remains. Take warm after meals. Subsequently, take equal parts of Luo Bo Zi (Raphani Semen, 萝卜子) and Xing Ren powder, made into pills with rice paste. Take 50 pills with Ginger Soup to eradicate the root of the disease.
[Discussion] Zhi Mu combines bitter and cold properties, firmly establishing it as a Kidney agent. However, since its taste is sweet and bitter, and bitter is accompanied by pungent, although bitterness predominates, starting with sweetness and ending with pungency, it cannot be denied that it enters the Qi aspect of the Lung and Stomach. (In the fourth month, flowering allows Qi to flow freely into Fire; in the eighth month, fruiting stores Qi in Metal.) The *Bencao Jing* states it tonifies deficiencies and benefits Qi, derived from its ability to eliminate pathogenic factors, reduce limb edema, and promote urination, which holds profound significance. The Classics state: The San Jiao (Triple Burner, 三焦) is the mansion of deep channels; water pathways emerge from it, belonging to the Bladder. It is the solitary mansion, associated with the six fu-organs. The Ministerial Fire of the San Jiao is the origin of Original Qi, belonging to the Bladder to facilitate water transformation. The Bladder indeed belongs to the Kidney. The Classics further state: The two Yin meridians connect to the Lung, their Qi returns to the Bladder, externally connecting to the Spleen and Stomach. As stated: When drink enters the Stomach, it overflows and transmits to the Spleen; Spleen Qi scatters essence, ascending to return to the Lung; regulating water pathways, transmitting downward to the Bladder; water essence distributes in all directions, traversing the five meridians. Does this not clarify the meaning of eliminating pathogenic factors, reducing limb edema? Indeed, water transformation is Qi transformation. The efficacy of this substance arises from the combination of Stomach and Lung applying its bitter-cold nature upward, and from the combination of Lung and Stomach reaching its bitter-cold transformation downward. Thus, it can clear Bladder Heat and Excess Ministerial Fire of the Kidney. The *Bencao Jing* clarifies tonifying deficiencies and benefiting Qi through promoting urination, precisely because it nourishes Yin via Yang and preserves Yang via Yin, aligning with the principle that Yin deficiency leads to lack of Qi, and lack of Qi leads to death. Regarding conditions such as flaming fire causing Lung cough, wasting-thirst with heat in the middle, mental irritability, Kidney Qi damage, heat-consumption (add for patients with deficiency and dry mouth), and bone-steaming fever, all achieve the benefit of benefiting Qi through clearing heat, not merely countering heat with cold. Furthermore, chronic malaria from Cold Damage damages acquired Post-Heaven Qi and Blood, affecting Pre-Heaven Essence; one must rely on this Metal-Water generating substance to overcome pathogenic heat and restore True Yin. Indeed, Tianyi True Yin is the origin of Post-Heaven Vital Qi; this is what the Classics mean by "benefiting Qi." However, due to its bitter-cold nature, users must examine suitability carefully to avoid damaging the vital Qi of the Central Earth and severing the root of Yin transforming into Yang.
Miao states: For impotence, easy erection and rapid flaccidity, weak Spleen failing to digest, deficient Stomach failing to receive, and Kidney deficiency with loose stools, these syndromes are strictly contraindicated.
[Processing] Select plump, moist, white-coated roots, remove hairs, and slice. For upward action, soak in wine and bake dry; for downward action, moisten with salt water and bake. Do not contact iron vessels.