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(The herbs with strong flavors belong to Yin within Yin. Strong flavors induce purgation. Sour, bitter, and salty flavors combined with cold nature exemplify this category.)

**Coptidis Rhizoma (Huanglian, 黄连):** Nature is cold, flavor is bitter, non-toxic. Its medicinal qi and flavor are both dense; its action can ascend or descend, belonging to Yang within Yin. It enters the Hand-Shaoyin Heart Meridian. Its functions are sixfold: first, it clears and drains Heart Fire; second, it removes damp-heat from the Middle Jiao; third, it is essential for treating various sores and ulcers; fourth, it dispels wind-dampness; fifth, it treats sudden onset of red eyes; sixth, it stops bleeding in the middle region. Zhang Zhongjing used it in all five varieties of Xixin Decoction (Clear the Heart Decoction) for treating nine types of epigastric fullness. [Li Dongyuan] states that Huanglian enters the Foot-Shaoyin Kidney Meridian because its bitter and drying nature allows it to address dryness in Heart Fire. However, "draining the Heart" actually refers to draining the Spleen, based on the principle that "the child can cause the mother to be excess," and thus excess in the child is drained. In treating blood disorders, Saposhnikoviae Radix (Fangfeng, 防风) serves as the ascending guide, Coptidis Rhizoma (Huanglian, 黄连) as the central agent, and Sanguisorbae Radix (Diyu, 地榆) as the descending agent. Remove the rootlets, chop finely, and prepare.

**Scutellariae Radix (Huangqin, 黄芩):** Nature is cold, flavor is bitter, non-toxic. Its action can ascend or descend, belonging to Yin with slight Yang within. It enters the Blood aspect of the Hand-Taiyang Small Intestine Meridian. [Zhang Yuansu] describes its nature as cool, flavor as bitter and sweet, with dense qi and thin flavor, floating and ascending, representing Yin within Yang. It enters the Hand-Shaoyang Gallbladder and Hand-Yangming Large Intestine Meridians. Wine-frying directs its action upward. [Li Dongyuan] notes that Scutellariae Radix which is hollow and light clears Lung Fire, promotes Qi movement, resolves phlegm, dispels wind-heat, and eliminates heat in the muscle layer. Those that are solid and heavy clear Large Intestine Fire, nourish Yin, subdue deficient Yang, tonify Bladder Cold Water, and nourish the source of transformation. The distinction between high and low usage parallels that of Aurantii Fructus Immaturus (Zhishi, 枳实) and Aurantii Fructus (Zhiqiao, 枳壳). [Zhang Yuansu] summarizes nine uses for Scutellariae Radix: first, clears Lung heat; second, removes wind-heat and wind-dampness from the upper Jiao skin; third, clears various heats; fourth, benefits Qi in the chest; fifth, eliminates phlegm in the diaphragm; sixth, removes dampness from the Spleen meridian; seventh, must be used in summer; eighth, nourishes Yin and subdues Yang postpartum in women; ninth, calms the fetus. Wine-fried to ascend, it treats accumulated blood in the upper body, indispensable for clearing such conditions. For dysentery with pus and blood, abdominal pain, tenesmus, and prolonged fever, combine with Paeoniae Radix Alba (Baishao, 白芍) and Glycyrrhizae Radix et Rhizoma (Gancao, 甘草). For painful sores, bitter-cold herbs like Coptidis Rhizoma are suitable; use according to upper/lower body differentiation and add guiding herbs. [Su Song] records that Zhang Zhongjing used Scutellariae Radix in all four Xixin Decoctions for epigastric fullness due to Shaoyin cold damage, as it treats various heats and benefits the Small Intestine. For Taiyang disease treated with purgatives leading to unceasing diarrhea, wheezing, and sweating, Gegen Huangqin Huanglian Tang (Kudzu, Scutellaria, and Coptis Decoction) is indicated. It is also widely used in AnTai San (Calming the Fetus Powder) for pregnancy. [Zhu Zhenheng] notes that Zhang Yuansu said Scutellariae Radix clears Lung Fire and treats Spleen dampness; Li Dongyuan said Pian Qin (slice Scutellaria) treats Lung Fire, Tiao Qin (strip Scutellaria) treats Large Intestine Fire; Zhu Zhenheng said it treats Upper and Middle Jiao fire. Zhang Zhongjing used it in Xiao Chaihu Tang (Minor Bupleurum Decoction) for Shaoyang syndrome, Huangqin Tang (Scutellaria Decoction) for Taiyang-Shaoyang combined disease with diarrhea, and Xixin Decoction for Shaoyang syndrome after purgation with epigastric fullness but no pain. Cheng Wuji stated that Scutellariae Radix's bitter taste enters the Heart to drain heat from fullness, indicating it enters the Hand-Shaoyin, Hand-Yangming, Foot-Taiyin, and Foot-Shaoyang meridians. Essentially, its cold nature and bitter flavor, yellow-green color, enter the Heart via bitterness, overcome heat via coldness, clear Heart Fire, and treat Spleen damp-heat. This prevents Metal (Lung) from being controlled by Fire (Heart) and prevents Stomach Fire from flowing into the Lung, thereby saving the Lung. However, it is unsuitable for Lung deficiency as bitter-cold damages the Spleen and Stomach, harming the Mother element. Shaoyang syndrome presents with alternating chills and fever, hypochondriac fullness, silence, lack of appetite, irritability, vomiting, or urinary difficulty. Although located at half-exterior/half-interior, hypochondriac fullness involves Upper Jiao pathogens of Heart and Lung, while irritability, vomiting, and silence involve Middle Jiao Spleen and Stomach symptoms. Thus, Scutellariae Radix treats the Ministerial Fire of Hand and Foot Shaoyang. It is a primary herb for the Shaoyang meridian. Cheng Wuji’s commentary only mentions Bupleuri Radix (Chaihu, 柴胡) and Scutellariae Radix bitterness to disperse transmitted heat, and Paeoniae Radix and Scutellariae Radix bitterness to consolidate intestinal Qi, missing the subtlety of treating Fire. Yang Shiyang claimed Chaihu is inferior to Scutellariae Radix for reducing fever, not realizing Chaihu disperses the branch of fire via bitterness, while Scutellariae Radix conquers the root of fire via coldness. Zhang Zhongjing also stated that for Shaoyang syndrome with abdominal pain, remove Scutellariae Radix and add Paeoniae Radix; for palpitations and urinary difficulty, remove it and add Poria (Fuling, 茯苓). This seems contradictory to Ben Cao regarding treating lower abdominal cramping and benefiting the Small Intestine. Cheng Wuji argued Scutellariae Radix is cold and bitter, hardening the Kidney, hence removed. This is likely incorrect. One must deduce through reasoning and pulse/symptom differentiation. If abdominal pain results from drinking cold water or contracting cold, with palpitations, urinary difficulty, and non-rapid pulse, there is no interior heat, so Scutellariae Radix is contraindicated. However, for heat-jue abdominal pain or Lung heat causing urinary difficulty, Scutellariae Radix is essential. Scholars should seek the underlying principle rather than sticking rigidly to text. Remove peel and black rot, chop finely, sieve with bamboo.

**Phellodendri Cortex (Huangbai, 黄柏):** Nature is cold, flavor is bitter, non-toxic. Medicinal qi and flavor are dense, sinking and descending, belonging to Yin. Bitter and slightly pungent, it represents Yang within Yin. It enters the Foot-Shaoyin Kidney Meridian and serves as a guiding herb for the Foot-Taiyang Bladder Meridian. [Li Dongyuan] treats kidney water and Bladder insufficiency causing various痿 (Wei) syndromes,厥 (Jue) syndromes, and weak knees/legs. Added in small amounts to Huangbai Tang, it generates strength in the knees, resolving Wei. Honey-fried and powdered, it miraculously treats mouth ulcers and is essential for paralysis. It drains Bladder heat, opens the lower orifices, drains Bladder meridian fire, and tonifies the meridian and Kidney insufficiency. The Classic states: "Bitter hardens." The Foot-Shaoyin Kidney fears dryness, leading to dampness retention. Gardenia (Zhizi, 栀子) and Scutellariae Radix enter the Lung; Coptidis Rhizoma enters the Heart; Phellodendri Cortex enters the Kidney; their drying properties follow their respective categories. Huoren Shu’s Jiedu Tang treats internal and external issues. Remove peel, chop. Raw use descends excess fire; wine-processed treats the upper body; salt-processed treats the lower body; honey-processed treats the middle body without damaging the Stomach.

**Gardeniae Fructus (Zhizi, 栀子):** Nature is cold, flavor is bitter, non-toxic. [Zhang Yuansu] describes it as having thin qi and dense flavor, light and clear ascending, floating qi and descending flavor, representing Yin within Yang. [Li Dongyuan] describes it as sinking, Yin, entering the Blood aspect of the Hand-Taiyin Lung Meridian. [Li Dongyuan] Ben Cao does not mention Zhizi as an emetic, but Zhang Zhongjing used it as such. Zhizi is not inherently an emetic; rather, pathogens in the upper region reject the medicine. Vomiting expels the pathogen, following the principle "those high above should be evacuated." Some use it to promote urination, but it actually clears the Lung. Clearing the Lung allows Qi transformation, enabling the Bladder to excrete fluids. Ben Cao says it treats Large and Small Intestine heat because Pungent combines with Geng (Metal), Bing (Fire), and泄 (Xie) Wu (Earth/Stomach), entering the Central State first. Zhang Zhongjing used Zhizi Chi Tang (Gardenia and Fermented Soybean Decoction) for irritability. Irritability (Fan) relates to Qi and the Lung; restlessness (Zao) relates to Blood and the Kidney. Zhizi treats Lung-related Fan; Chi Xiao Dou (Fermented Soybean) treats Kidney-related Zao. Zhang Zhongjing noted Zhizi’s red color and bitter taste enter the Heart to treat Fan; Chi Xiao Dou’s black color and salty taste enter the Kidney to treat Zao. [Kou Zongshi] records Zhang Zhongjing using Zhizi Chi Tang for insomnia and mental agitation after sweating, vomiting, or purging for cold damage, avoiding Da Huang (Rhubarb) due to its cold toxicity. Zhizi is cold but non-toxic, treating stomach heat. After loss of blood and fluids, internal deficiency heat arises, requiring Zhizi. For Heart meridian residual heat with dark/scanty urine, combine peeled Zhizi, fire-roasted Da Huang, Forsythiae Fructus (Lianqiao, 连翘), and roasted Glycyrrhizae Radix et Rhizoma in equal parts. Take 3 qian decocted in water. Select Zhizi resembling a sparrow’s brain with nine ridges and red color. Use the kernel for chest heat, the peel for surface heat, whole fruit for Upper/Middle Jiao, shelled for Lower Jiao, and charred for blood disorders.

**Gypsum Fibrosum (Shigao, 石膏):** Nature is cold, flavor is sweet and pungent, non-toxic. Enters the Hand-Taiyin Lung, Hand-Shaoyang Sanjiao, and Foot-Yangming Stomach meridians. [Zhang Yuansu] describes it as cold, sweet-pungent, bland, thin in qi/flavor, heavy, sinking, and Yin. It is a major cold herb for the Yangming meridian, treating headache, toothache, thirst, heatstroke, and tidal fever. However, it can chill the Stomach and suppress appetite, so avoid unless there is extreme interior heat. It treats Yangming heat with fever, aversion to cold, dryness, afternoon tidal fever, muscular fever, turbid/dark urine, intense thirst, spontaneous sweating, and severe headache. Zhang Zhongjing used Baihu Tang (White Tiger Decoction) for this. Do not use if these symptoms are absent. Many cases of blood-deficiency fever mimicking Baihu syndrome, or Spleen-Stomach deficiency, are misdiagnosed and mistreated, leading to untreatable outcomes. [Li Dongyuan] states Gypsum belongs to the Foot-Yangming meridian. Zhang Zhongjing used it for Yangming syndrome with fever, eye pain, nasal dryness, and insomnia. The face/chest area corresponds to the Stomach meridian and Lung residence. Pathogens in Yangming affect the Lung via Fire control, so pungent-cold herbs clear Lung Qi, hence the name White Tiger. It also treats Sanjiao skin heat, entering the Hand-Shaoyang meridian. Use for persistent rapid pulses. Avoid in weak Stomachs. For warm-heat diseases with irritability, thirst, and surging-rapid-long pulses, Gypsum is essential, even in winter. Zhang Zhongjing formulated Baihu Tang for standard cold damage. Li Dongyuan’s advice to avoid it after End of Heat is too rigid. This is the same as Hanshui Shi (Cold Water Stone) or Ying Shigao (Hard Gypsum). Fine white texture is best. Crush to millet size, boil dozens of times before adding other herbs as its essence is hard to extract.

**Anemarrhenae Rhizoma (Zhimu, 知母):** Nature is cold, flavor is bitter, dense in qi/flavor, sinking, Yin with slight Yang. It is a primary herb for the Kidney meridian, entering the Qi aspect of the Foot-Yangming Stomach and Hand-Taiyin Lung meridians. [Li Dongyuan] has four uses: drains rootless Kidney Fire, treats bone-steaming with sweat, stops deficiency heat, and nourishes the Yin of the transformation source. Zhang Zhongjing added it to Baihu Tang for insomnia and irritability. Fan originates from the Lung, Zao from the Kidney. Gypsum is the sovereign, Zhimu the assistant, using bitter-cold to clear the Kidney source. Licorice and Coix Seed slow the descent. For urinary obstruction with thirst, heat is in the Upper Jiao Qi aspect; Lung latent heat fails to generate Water, cutting off the Bladder’s source. Use thin-qi/thin-flavor diuretics to drain Lung Fire and nourish Water. For heat in the Lower Jiao Blood aspect without thirst, true Water is insufficient, Bladder is dry, and Yang cannot transform without Yin. Use Phellodendri Cortex and Anemarrhenae Rhizoma (bitter-cold) to tonify Kidney and Bladder, allowing Yin to move and Yang to transform, restoring urination. Select plump, white-inside rhizomes, remove hairs, slice. For ascending guidance, wine-soak and roast; for descending, salt-water moisten and roast. (Avoid iron).

**Fraxini Cortex (Qinpi, 秦皮):** Nature is cold, flavor is bitter, non-toxic. Sinking and descending. [Li Dongyuan] treats heat-dysentery with heaviness and lower Jiao deficiency. The Classic states "Bitter hardens," hence used with Polygalae Radix (Baitouweng, 白头翁) and Phellodendri Cortex. Treats wind-cold-damp bi, ocular nebula/membrane, male scant sperm, female leukorrhea, pediatric convulsions. Best as a wash for eyes. Known as Bai Mu; soak bark in water for blue color. Combine with Lithospermi Radix (Zicao, 紫草) for better effect. Euphorbiae Humifusa Herba (Daji, 大戟) is its assistant; adverse with Evodiae Fructus (Wuzhuyu, 吴茱萸). [Zhu Zhenheng] Qinpi is green, cold-bitter-astringent, entering the Jueyin Liver and Shaoyang Gallbladder meridians. Treats eye disorders and convulsions by calming Liver Wood; treats dysentery, metrorrhagia, and leukorrhea by astringency. Benefits male fertility via astringent tonification. Laozi said Heaven values astringency. It is suitable for food therapy and convulsions/dysentery, yet often neglected except for eye treatment, which is regrettable.

**Pulsatillae Radix (Baitouweng, 白头翁):** Nature is cold, flavor is bitter-pungent, non-toxic. Dense qi, thin flavor, ascending/descending, Yang within Yin. Treats warm malaria, mania, chills/fever, masses, moves blood, stops pain. Zhang Zhongjing used Baitouweng Tang for heat-dysentery with urgency. The Kidney desires firmness, aided by bitter taste. Dysentery causes lower Jiao deficiency, so pure bitter herbs firm it. Treats hernia, pediatric alopecia/seborrhea, epistaxis, and toxic dysentery effectively. [Wu Qiu] Suitable for heat-toxin dysentery with purple/fresh blood.

**Rhei Radix et Rhizoma (Dahuang, 大黄):** Nature is cold, flavor is bitter, non-toxic. Dense qi/flavor, sinking, Yin. Use wine-soaked and baked versions; "cold treated with heat." Wine infusion enters the Taiyang meridian; wine-washing enters the Yangming meridian. [Li Dongyuan] Rhubarb is bitter,峻 (forceful) in downward movement. Use raw for lower body pathogens. For upper body pathogens, wine is necessary to guide the herb high to drive heat down, like shooting targets high up. Raw use leaves high pathogens, causing post-recovery eye redness, throat bi, head swelling, or diaphragm heat. [Kou Zongshi] Zhang Zhongjing used Rhubarb, Scutellariae Radix, and Coptidis Rhizoma in Xixin Decoction for Heart Qi deficiency causing hematemesis/epistaxis. Question: Why not tonify Heart Qi? Answer: Pure deficiency wouldn’t cause bleeding; it’s pathogenic heat exploiting deficiency. Bitterness tonifies the Heart. Effective if matched to deficiency/excess. [Zhu Zhenheng] Rhubarb is bitter-cold and purgative. Used in Xixin Decoction because Shaoyin deficiency leads to hyperactive Yang and wild bleeding. Rhubarb drains excess fire to restore peace. Heart Yin deficiency is chronic; Lung and Liver suffer from Fire. Scutellaria saves the Lung; Coptis saves the Liver. Once Liver/Lung fire subsides, Yin blood returns to normal. Kou’s explanation of "pathogenic heat" is unclear. [Zhu Zhenheng] Rhubarb enters the Blood aspect of Foot-Taiyin, Hand/Foot-Yangming, and Hand/Foot-Jueyin meridians. Use for Blood aspect disorders; using it for Qi aspect is unjustified punishment.

**Xixin Decoction:** Treats Heart Qi deficiency with bleeding. True Heart Qi is deficient, while Hand-Jueyin Pericardium, Foot-Jueyin Liver, Foot-Taiyin Spleen, and Foot-Yangming Stomach have excess evil fire. "Draining Heart" actually drains latent fire in these four meridians' blood. For epigastric fullness soft to touch, Dahuang Huanglian Xixin Tang is used to drain Spleen-Stomach damp-heat, not the Heart. Yin disease treated with purgatives causes fullness; cold injures Nutritive Blood, pathogens bind in Upper Jiao/Stomach, affecting the Heart. Hence "draining Heart" means draining Spleen. Suwen states Taiyin causes fullness, and turbid Qi rising causes distension. Yang disease treated with purgatives causes Jie Xiong (chest binding); heat enters Blood aspect in Upper Jiao. Daxiexiong Tang/Pills use Rhubarb to drain Spleen-Stomach Blood evil and descend turbid Qi. For Qi-level Jie Xiong, Xiaoxiexiong Tang is used; for Qi-level fullness, Banxia Xiexin Tang is used. Cheng Wuji failed to distinguish this. [Su Song] Ben Cao praises Rhubarb for pushing out old and generating new. Ancients used toxic drugs carefully based on constitution. Emperor Wu of Liang wanted Rhubarb for fever; Yao Shengtan warned against it due to age. Emperor ignored him and nearly collapsed. Emperor Yuan of Liang had abdominal issues; doctors suggested mild herbs, but Yao insisted on Rhubarb for pulse evidence of stagnation, curing him. Modern doctors misuse toxic drugs, claiming success when lucky but hiding errors. Remove peel, chop, sieve.

**Natrii Sulfas (Mangxiao, 芒硝):** Nature is greatly cold, flavor is salty-bitter-pungent, slightly toxic. [Cheng Wuji] Neijing states salty flavor drains downward (Yin) and softens hardness. Heat inside is treated with salty-cold. Hardness is softened by salty; excess heat is cleared by cold. Zhang Zhongjing used Mangxiao in Daxiexiong Tang, Dachengqi Tang, and Tiaowei Chengqi Tang to soften hardness and drain excess heat. Not for non-hard conditions. [Li Dongyuan] Ben Cao says Puxiao (Mirabilite) is pungent to moisten Kidney dryness; now only salty is used to soften hardness. Ben Cao says Mangxiao promotes urination and aborts, but in cold damage/pregnancy requiring purgation, combined with Rhubarb, it moisturizes, softens, and drains heat, protecting mother and fetus. Neijing: "If there is pathology, no injury occurs." Regarding lower body, urination/defecation are Yin; anterior is Qi, posterior is Blood; Kidney governs both. Urinary difficulty/stool constipation result from water deficiency and fire excess. Neijing: treat heat with salty-cold, assisted by bitter. Thus, Mangxiao and Rhubarb are synergistic. [Zhang Yuansu] Mangxiao is thin-qi/dense-flavor, sinking, Yin. Three uses: drains excess heat, cleansse gut residue, breaks heat masses. [Zhu Zhenheng] Puxiao is crude, forceful, for rough constitutions or external use. Mangxiao is refined Puxiao, milder, preferred by Zhang Zhongjing. Mangxiao inherits Taiyin essence, Water’s child, cold-salty, enters Blood, moistens downward, cleanses Sanjiao/Gut excess heat, treats Yang-excess fire. Use raw.

**Fermented Soybean (Xiangchi, 香豉):** Nature is cold, flavor is bitter, non-toxic, Yin within Yin. Treats cold damage headache, irritability, fullness. Use raw. [Zhu Zhenheng] Black bean is neutral; fermented becomes warm. Steaming/fermenting allows ascending/dispersing. With Scallion: induces sweat; with Salt: induces vomiting; with Wine: treats wind; with Allium macrostemon (Xie, 薤): treats dysentery; with Garlic: stops bleeding; cooked: stops sweat significantly. Similar to Ephedrae Caulis (Mahuang Genjie, 麻黄根节).

**Artemisiae Scopariae Herba (Yinchenhao, 茵陈蒿):** Nature is slightly cold, flavor is bitter-pungent, non-toxic, slight Yang within Yin. Enters Foot-Taiyang Bladder meridian. Clears irritability/heat, treats wind-cold-damp-heat, heat-binding jaundice, generalized yellowing, urinary difficulty. [Kou Zongshi] Zhang Zhongjing used it effectively for severe heat jaundice. A monk had lingering heat jaundice after incomplete sweating; dietary therapy failed. Given this herb: 1/3 improvement in 5 days, 2/3 in 10 days, cured in 20 days. Formula: Shan Yinchen and Gardeniae Fructus 3 fen, Qinghao (Qinjiao, 秦艽) and Cimicifugae Rhizoma (Shengma, 升麻) 4 qian. Powder, take 3 qian with water, decoct, take warm after meals. Based on Shan Yinchen. [Li Dongyuan] Yinchenhao Tang/Zhizi Dahuang Tang treat damp-heat; Zhizi Baipi Tang treats dry-heat. Wet yellow requires draining; dry yellow requires moistening. These two treat Yang Jaundice. Han Zhihe and Li Sixun used Yinchen Fuzi Tang for Yin Jaundice. Yinchen is sovereign, assisted by Rhubarb/Aconite per cold/heat. Remove stems, use leaves, crush by hand.

**Trichosanthis Fructus (Gualou Shi, 栝蒌实):** Nature is cold, flavor is sweet-mild bitter, non-toxic. [Zhu Zhenheng] Treats chest bi (pain/oppression) due to sweet-moist nature tonifying Lung and descending Qi. Phlegm caused by Lung Fire losing descending function is resolved by sweet-moist help, making it key for cough. Also washes away greasy郁 (depressed) heat in chest/diaphragm, miraculous for thirst-quenching. [Zhu Zhenheng] Zhang Zhongjing used it for chest bi radiating to back, coughing saliva, wheezing, and chest binding pain. Its sweet-cold nature doesn’t harm Stomach Qi, descends Upper Jiao fire, and moves phlegm-Qi. Cheng Wuji mistakenly called it bitter-cold to drain heat, ignoring its actual sweet taste. Use large, firm fruits with seeds and peel, finely sliced. Using only kernels is incorrect.

**Trichosanthis Radix (Gualou Gen / Tianhuafen, 栝蒌根/天花粉):** Nature is cold, flavor is sweet-mild bitter-sour, non-toxic. Treats thirst, fever, irritability, great heat, deficiency, calms spirit, regulates menstruation, reduces swelling/toxins, blood stasis, heat-manía, sores. [Li Dongyuan] Pure Yin, quenches thirst, moves fluids, cures heart dryness. Combined with pungent-sour to guide swelling Qi. [Zhu Zhenheng] Sweet-mild bitter-sour. Stem/leaf sourness generates fluids, quenching thirst and moistening dryness. Mild bitter drains fire, sweet doesn’t harm Stomach. Past texts calling it merely bitter-cold missed depth. Finely grind and sieve.

**Polypodi Rhizome (Tugua Gen, 土瓜根):** Nature is cold, flavor is bitter, slightly toxic. Treats various pathogens, heat-binding, water in joints across seasons, epidemic fevers, alcohol jaundice, fever/irritability, consumption, induces vomiting/purgation.

**Forsythiae Radix (Lianyao, 连轺):** Nature is cold, flavor is sweet-bitter, slightly toxic. Descends heat, nourishes Yin essence. Zhang Zhongjing used Mahuang Lianyao Chixiaodou Tang for cold damage with trapped heat/jaundice.

**Bambusae Folium (Zhuye, 竹叶):** Nature is cold, flavor is sweet, non-toxic. Bambusa vulgaris (Dan Zhu, 淡竹) is superior; Bambusa textilis (Gan Zhu, 甘竹) secondary. Treats chest phlegm-heat, cough, rebellious Qi. [Kou Zongshi] Bamboo shoots are cold, so leaves share this property. Zhang Zhongjing’s Zhuye Tang uses Dan Zhu. [Zhang Yuansu] Bitter-flat, slight Yang within Yin. [Li Dongyuan] Bitter-pungent-cold, ascending/descending, Yin within Yang. Two uses: clears new/old wind-pathogen heat, stops wheezing/rebellious Qi.

**Morus Cortex (Zibai Pi, 梓白皮):** Nature is cold, flavor is bitter, non-toxic. Treats heat-toxins, expels parasites, seasonal warm diseases, headache, fever. Use fresh Mulberry wood bark (inner white part) on day one.