Home > Herb database > Shi Wei

Pyrrosia leaves

Chinese: 石韦

Pinyin: Shí Wéi

Parts used: Dried leaves

TCM category: Herbs that drain Dampness

TCM nature: Cool

TCM taste(s): BitterSweet

Organ affinity: Bladder Lung

Scientific name: Pyrrosia sheareri, Pyrrosia lingua or Pyrrosia petiolosa

Use of pyrrosia leaves (Shi Wei) in TCM

Please note that you should never self-prescribe TCM ingredients. A TCM ingredient is almost never eaten on its own but as part of a formula containing several ingredients that act together. Please consult a professional TCM practitioner, they will be best able to guide you.

Preparation: Extract the leaves, clean them and let them dry, preferably under the sun

Dosage: 6-16 g

Main actions according to TCM*: Clears Damp-Heat, unblocks painful urinary dysfunction, clears urinary stones. Removes Heat and arrests bleeding. Clears the Lungs, expels Phlegm and stops coughing.

Primary conditions or symptoms for which pyrrosia leaves may be prescribed by TCM doctors*: Urinary tract infection Urolithiasis Bloody sputum Abnormal uterine bleeding Coughing Asthma

Common TCM formulas in which pyrrosia leaves (Shi Wei) are used*

Shi Wei San

Source date: 1687 AD

Number of ingredients: 5 herbs

Formula key actions: Clears heat. Promotes the resolution of Dampness. Unblocks painful urinary dribbling. Expels stones.

Conditions targeted*: UrethritisCystitis and others

Read more about Shi Wei San

Key TCM concepts behind pyrrosia leaves (Shi Wei)'s properties

In Traditional Chinese Medicine (TCM), pyrrosia leaves are plants that belong to the 'Herbs that drain Dampness' category. These herbs are typically diuretics, meaning that they promotes the increased production of urine in order to remove Dampness that has accumulated in the body. According to TCM Dampness accumulates first in the lower limbs, causing edema and impaired movement. From there, if unchecked, it can move upward and impair digestion and eventually the respiratory system.

Furthermore pyrrosia leaves are plants that are Cool in nature. This means that pyrrosia leaves tend to help people who have too much 'Heat' in their body, although with less effect than a plant that would be Cold in nature. Balance between Yin and Yang is a key health concept in TCM. Those who have too much Heat in their body are said to either have a Yang Excess (because Yang is Hot in nature) or a Yin deficiency (Yin is Cold in Nature). Depending on your condition pyrrosia leaves can help restore a harmonious balance between Yin and Yang.

Pyrrosia leaves also taste Bitter and Sweet. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Bitter ingredients like pyrrosia leaves tend to have a cleansing action on the body by clearing Heat, drying Dampness and promoting elimination via urination or bowel movements. On the other hand Sweet ingredients tend to slow down acute reactions and detoxify the body. They also have a tonic effect because they replenish Qi and Blood.

The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such pyrrosia leaves are thought to target the Bladder and the Lung. In TCM the impure water collected by the Kidneys that cannot be used by the body is sent to the Bladder for storage and excretion as urine. In addition to performing respiration, the Lungs are thought in TCM to be a key part of the production chain for Qi and the Body Fluids that nourish the body.