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Tongcao, anciently known as *Tongduomu* (Acanthopanax gracilistylus stem).
Its properties are light, penetrating, diuretic, and heat-clearing.
Its color is white, its nature is cold, its texture is light, and its taste is bland. Its cold nature descends, so it enters the Lung Meridian, guiding heat downward to promote urination; its bland taste ascends, so it enters the Stomach Meridian, promoting Qi circulation upwards to facilitate lactation. It treats five types of strangury (Wu Lin) and edema, blurred vision, deafness, nasal congestion, and loss of voice (due to its blandness opening orifices, coldness descending fire, and benefiting Lung Qi), clears heat, and induces labor.

Zexie (Alisma Rhizome) penetrates, promotes urination, and drains Bladder Fire.
Its taste is sweet, bland, and slightly salty. It enters the Bladder Meridian, promotes urination, drains Fire pathogenic factors from the Kidney Meridian, and its efficacy specializes in dispelling dampness and moving water.
It treats thirst (Xiao Ke), phlegm-fluid retention, vomiting, diarrhea, dysentery, swelling, water-type palpitations (Shui Pi), podagra (Hong Kong Jiao - gouty arthritis of the foot), hernia pain, dribbling strangury, and scrotal sweating (Yin Han - sweating in the genital area), hematuria, and seminal emission (it can both promote urination and stop seminal emission; why? This is because the disease is caused by Damp-Heat. This does not refer to deficiency-type sliding/leakage; for deficiency-sliding, astringent and tonifying herbs should be used). It treats diseases of Damp-Heat.
Once Damp-Heat is eliminated, clear Qi ascends. It can also nourish the Five Zang Organs, benefit Qi and strength, raise Yin Qi, tonify deficiency and damage, stop dizziness, and has the effects of improving hearing and clarifying vision (If there is Damp-Heat in the Spleen and Stomach, there will be heavy head, tinnitus, and blurred vision. By渗 [shèn] - leaching out dampness, heat goes with it, Earth [Spleen] functions normally, and Essence-Qi ascends. Thus, *Shennong Ben Cao Jing* lists it in the Superior Grade, stating it improves hearing and vision. It is used in Liuwei Dihuang Wan, yet many today doubt it due to fears of blurring vision). Excessive consumption causes blurred vision (because excessive urination depletes Kidney Water. Fluids in the eyes belong to the Bladder; excessive draining leads to dryness and generation of Fire. Zhang Zhongjing uses Zexie in Bawei Wan. Kou Zongshi believed it guides Guizhi and Fuzi into the Kidney Meridian. Li Shizhen said: It is not for guidance, but to drain pathogenic factors from the Bladder. Ancients using tonics always combined them with draining herbs; once pathogens are removed, tonics work effectively. Closing and opening, this is the profound mystery. Later generations did not understand this, focusing solely on tonification, inevitably leading to imbalance. Wang Lü said: Shudi, Shanzhuyu, Fuling, Mudanpi are all Kidney Meridian herbs; Guizhi and Fuzi are Right Kidney Mingmen herbs; what need is there for guidance? Qian Yitian said: The Kidney is True Water, having only tonification without draining. Some say Spleen deficiency and Kidney excess require draining the Kidney to support the Spleen, not knowing that True Water of the Kidney cannot be drained, only latent pathogens. Spleen likes dryness, Kidney dislikes dryness, so combining tonification is difficult. Yi Lao said: It removes residue in the bladder because its slight saltiness drains stagnant water. Ang notes: Liuwei Dihuang Wan contains the warmth of Shudi, coolness of Mudanpi, astringency of Shanyao, permeability of Fuling,收敛 (shōu liǎn) - gathering/astringency of Shanzhuyu, and draining action of Zexie. Tonifying the Kidney while supporting the Spleen, having both tonification and draining, harmonizing and assisting each other to achieve balanced tonification, this is the miracle in plainness, hence an unchanging excellent prescription since antiquity. Even with modifications, adding one placenta (Ziheche), or Wuweizi, Maidong, Duzhong, Niuxi, etc., no more than one or two ingredients, at most three or four. Modern people often doubt the draining action of Zexie and remove it, arbitrarily adding various tonic herbs from materia medica, tonifying without draining. Moreover, if accessory herbs exceed main herbs in dosage, responsibility is not focused, and the efficacy of Liuwei Dihuang Wan retreats to a secondary position, losing the original intent of formula composition. This is the error of mediocre physicians in recent times).
Use after mixing with salt water or soaking in wine. Avoid iron.