What patterns does Shi Wei address?

Shi Wei addresses these TCM patterns of disharmony: Damp-Heat, Lung Heat, Blood Heat.

What conditions is Shi Wei used for?

Shi Wei is commonly used for: Urinary Tract Infection, Kidney Stones, Hematuria, Painful Urination, Chronic Bronchitis, Hypochondrial Pain That Is Worse On Coughing And Breathing, Bleeding, Nosebleed (Epistaxis), Nephritis, Asthma. A TCM practitioner would consider this herb when these conditions arise from the specific patterns it addresses.

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Herb Leaf (叶 yè)

Shi Wei

Q: What are the TCM actions of Shi Wei?

The TCM actions of Shi Wei include: Promotes Urination and Relieves Stranguria, Clears Lung Heat and Stops Cough, Cools the Blood and Stops Bleeding.

Pyrrosia leaf · 石韦

Pyrrosia lingua (Thunb.) Farw. · Pyrrosiae Folium

Also known as: Shi Wei (石苇)

Images shown are for educational purposes only

Shi Wei (Pyrrosia leaf) is a fern leaf used in Chinese medicine primarily for urinary problems such as painful urination, urinary stones, and blood in the urine. It clears heat from both the Urinary Bladder and the Lungs, so it is also used for coughs and bronchitis. Additionally, it helps stop bleeding caused by excess internal heat.

Category Dampness-draining herbs (利水渗湿药)

Therapeutic focus Urinary Health Kidney Stone Support Respiratory Health Bleeding Disorders

TCM Properties

Temperature

Slightly Cool

Taste

Sweet (甘 gān), Bitter (苦 kǔ)

Channels entered

Lungs, Urinary Bladder

Parts used

Leaf (叶 yè)

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What This Herb Does

Every herb has a specific set of actions — here's what Shi Wei does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Shi Wei is primarily used to support these areas of health:

Urinary Health Kidney Stone Support Respiratory Health Bleeding Disorders

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Shi Wei performs to restore balance in the body:

Promotes Urination and Relieves Stranguria Clears Lung Heat and Stops Cough Cools the Blood and Stops Bleeding

How these actions work

'Promotes urination and treats painful urinary dysfunction' (利尿通淋 lì niào tōng lín) is Shi Wei's primary action. In TCM, 'lin syndrome' covers a range of urinary problems including painful, burning, or difficult urination, often with urgency or the passage of sediment. Shi Wei's bitter and sweet taste combined with its cool nature allows it to clear heat and dampness from the Urinary Bladder, restoring normal water flow. This makes it especially useful for hot, painful, bloody, or stone-type urinary complaints. Classical sources such as the Shen Nong Ben Cao Jing record that it 'treats the five types of urinary blockage and promotes the water passages.'

'Clears Lung Heat and stops coughing' (清肺止咳 qīng fèi zhǐ ké) refers to Shi Wei's ability to enter the Lung channel and cool excess heat there. When the Lungs are overheated, a person may experience coughing, wheezing, or thick phlegm. Shi Wei's cool, bitter nature descends and clears this heat, helping to calm coughs. It has been used in modern clinical practice for both acute and chronic bronchitis.

'Cools the Blood and stops bleeding' (凉血止血 liáng xuè zhǐ xuè) means Shi Wei helps control bleeding that arises from heat driving the blood recklessly out of the vessels. This includes blood in the urine, nosebleeds, coughing up blood, and heavy or prolonged menstrual bleeding. Because it both cools heat and stops bleeding, it is particularly well suited for bleeding conditions where heat is the underlying driver.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Shi Wei is used to help correct these specific patterns.

Why Shi Wei addresses this pattern

Shi Wei is one of the most characteristic herbs for Bladder Damp-Heat. Its cool, bitter nature directly clears heat and dampness from the Urinary Bladder channel, while its sweet taste gently moistens the urinary tract. By promoting urination and clearing heat simultaneously, it addresses the core pathomechanism of this pattern: damp-heat steaming in the lower burner and obstructing the Bladder's function of transforming and excreting urine. The herb restores normal urine flow and resolves the burning, painful quality caused by heat in the Bladder.

A practitioner would look for one or more of these signs

Painful Urination

Burning, urgent, painful urination (the hallmark of hot lin syndrome)

Hematuria

Blood in the urine from heat damaging the Bladder vessels

Frequent Urination

Frequent, scanty urination with a feeling of incomplete emptying

Urinary Tract Infection

Dark, concentrated urine with possible sediment

Commonly Used For

These are conditions where Shi Wei is frequently used — but only when they arise from the specific patterns it addresses, not in all cases

Arises from: Damp-Heat

TCM Interpretation

In TCM, urinary tract infections are most often understood as Bladder Damp-Heat. Dampness and heat accumulate in the lower burner and obstruct the Bladder's ability to transform and discharge urine. This produces the classic symptoms of frequent, urgent, burning urination with dark or cloudy urine. The condition can arise from external dampness invading upward, from internal heat (dietary, emotional), or from a combination of both. When heat damages the small vessels of the Bladder, blood may appear in the urine, turning the condition into blood lin (血淋).

Why Shi Wei Helps

Shi Wei directly enters the Urinary Bladder channel with its cool, bitter nature, making it ideally suited for this condition. It clears damp-heat from the Bladder and restores normal urine flow, relieving the burning and urgency. Because Shi Wei also cools the Blood and stops bleeding, it is especially helpful when the infection involves hematuria. Clinical reports have documented its effectiveness in treating both upper and lower urinary tract infections, and it is a key ingredient in compound preparations such as Compound Shi Wei Tablets (复方石韦片) used specifically for urinary infections.

Arises from: Damp-Heat

TCM Interpretation

Kidney and urinary stones are classified in TCM as stone lin (石淋 shí lín). The pathomechanism involves prolonged accumulation of damp-heat in the lower burner, which 'cooks' and concentrates urine, eventually causing minerals to solidify into stones. Qi stagnation in the Bladder further obstructs the passage of these stones, causing intense pain. The condition is often aggravated by dietary factors (rich, greasy, or overly salty foods) and by inadequate fluid intake.

Why Shi Wei Helps

Shi Wei has been used for stone lin since antiquity. The Shen Nong Ben Cao Jing records its ability to treat urinary blockage. Its diuretic action increases urine volume, helping to flush small stones and sediment from the urinary tract. Its heat-clearing properties address the underlying damp-heat that promotes stone formation. Modern research has shown that Pyrrosia lingua extracts can alter the crystalline morphology of calcium oxalate in animal models, suggesting a mechanism for preventing stone aggregation. Shi Wei is a core ingredient in the classical Stone Lin formula (石韦散) where it is combined with Hua Shi (Talcum) to promote stone passage.

Also commonly used for

Hematuria

For blood in urine from heat, often combined with Pu Huang and Dang Gui

Painful Urination

Painful, burning urination from Bladder Damp-Heat

Hypochondrial Pain That Is Worse On Coughing And Breathing

Cough from Lung Heat, especially with thick phlegm

Bleeding

Uterine bleeding from Blood Heat, traditionally taken as powder with warm wine

Nosebleed (Epistaxis)

Nosebleeds related to blood heat

Nephritis

Used clinically for acute and chronic glomerulonephritis and pyelonephritis

Asthma

Bronchial asthma with Lung Heat component

Herb Properties

Every herb has an inherent temperature, taste, and affinity for specific channels — these properties determine how it interacts with the body

Temperature

Slightly Cool

Taste

Sweet (甘 gān), Bitter (苦 kǔ)

Channels Entered

Lungs Urinary Bladder

Parts Used

Leaf (叶 yè)

Dosage & Preparation

These are general dosage guidelines for Shi Wei — always follow your practitioner's recommendation, as dosages vary based on the formula and your individual condition

Standard dosage

6-12g

Maximum dosage

Up to 30g in chronic bronchitis or severe urinary conditions, under practitioner supervision. Some clinical reports have used even higher doses (45-50g equivalent of fresh herb) for acute bronchial asthma in adults, but this requires professional guidance.

Dosage notes

The Chinese Pharmacopoeia standard dosage is 6-12g in decoction. For urinary conditions such as painful urination, blood in the urine, or urinary stones, the standard range is usually sufficient. For chronic bronchitis and lung-related coughs, clinical reports have used higher doses of 15-30g for extended treatment courses of 10 days or more. When used as a powder (ground and taken directly), traditional doses are smaller, around 6-9g per dose. In clinical practice for chronic nephritis, treatment courses typically run about 3 months. For acute conditions, 10 days may suffice.

Preparation

Traditionally, the stellate hairs on the underside of the leaves were scraped or brushed off before use (去毛), as they were thought to irritate the throat and lungs if ingested. Modern processing (cut into segments, washed, dried) typically addresses this. No special decoction handling such as pre-decoction or late addition is required.

Processing Methods

In TCM, the same herb can be prepared in different ways to change its effects — here's how processing alters what Shi Wei does

Processing method

The star-shaped hairs (stellate trichomes) on the underside of the leaf are scraped or brushed off before use. This is the standard preparation method referenced in most classical formulas as 'Shi Wei (qu mao).'

How it changes properties

Removing the hairs does not significantly change the thermal nature or taste. The purpose is practical: the fine hairs can irritate the throat and lungs if ingested, potentially causing coughing. Removing them ensures the herb can be taken as a decoction or powder without this side effect.

When to use this form

This is the standard form for all internal use. Nearly all classical prescriptions specify 'Shi Wei (qu mao)' meaning the hairs must be removed before decocting or grinding into powder.

Common Herb Pairs

These ingredients are traditionally combined with Shi Wei for enhanced therapeutic effect

Hua Shi 1:1 (equal parts, as in the classical Shi Wei San from Gu Jin Lu Yan Fang)

Shi Wei clears Bladder heat and promotes urination while Hua Shi (Talcum) provides a slippery, lubricating quality that helps dissolve and expel urinary stones. Together they both clear damp-heat and physically facilitate the passage of stones or sediment through the urinary tract, producing a stronger effect on stone lin than either herb alone.

When to use: Urinary stones (stone lin) with painful, difficult urination. Also useful for hot lin with burning urination and sediment in the urine.

Che Qian Zi 1:1 (equal parts)

Both herbs promote urination and clear heat, but Che Qian Zi (Plantain seed) has a stronger diuretic effect and also clears Liver heat and brightens the eyes. Together they powerfully increase urine output and clear damp-heat from the Bladder, amplifying each other's ability to treat painful urinary dysfunction.

When to use: Hot lin with painful, scanty urination and dark urine, especially when heart heat transfers to the small intestine. This is the pairing in the Shi Wei Tang from Quan Sheng Zhi Mi Fang.

Pu Huang 2:1 (Shi Wei 60g : Pu Huang 30g, as per classical sources)

Shi Wei cools the Blood and promotes urination while Pu Huang (Typha pollen) invigorates Blood, stops bleeding, and promotes urination. Together they address blood lin (血淋) by simultaneously cooling heat in the Blood, stopping urinary bleeding, and clearing the Bladder.

When to use: Blood lin (blood in the urine) caused by heat driving blood out of the vessels. This is a classic pairing from the Shi Wei San in Qian Jin Yao Fang, where it appears alongside Dang Gui and Shao Yao.

Qu Mai 1:1

Both herbs clear Bladder heat and promote urination, but Qu Mai (Dianthus) has a stronger action of breaking through Blood stasis in the urinary tract. Together they form a potent combination for clearing damp-heat, unblocking urinary obstruction, and addressing both heat and blood stasis in the Bladder.

When to use: Severe hot lin or stone lin with marked urinary obstruction, as used together in the classical Shi Wei San (Zheng Zhi Zhun Sheng) and in Bie Jia Jian Wan.

Key Formulas

These well-known formulas feature Shi Wei in a prominent role

Shi Wei San 石韦散 King

The namesake formula for this herb. Shi Wei San is the definitive lin-treating formula where Shi Wei serves as King, showcasing its core action of clearing Bladder Damp-Heat and promoting urination. The original version from Gu Jin Lu Yan (via Wai Tai Mi Yao) pairs Shi Wei with Qu Mai, Hua Shi, Che Qian Zi, and Dong Kui Zi to treat all types of lin syndrome including stone lin and hot lin.

Bie Jia Jian Wan 鳖甲煎丸 Assistant

Zhang Zhongjing's classical formula from the Jin Gui Yao Lue for treating malaria masses (疟母). Shi Wei serves as Assistant, contributing its water-draining and heat-clearing properties to a complex formula that softens hardness and breaks accumulations. The Chang Sha Yao Jie notes Shi Wei's role here is 'to drain water and disperse stasis.'

Comparable Ingredients

These ingredients have overlapping uses — here's how to tell them apart

Shi Wei vs Hai Jin Sha

Both Shi Wei and Hai Jin Sha (Lygodium spore) promote urination and treat lin syndromes, but they differ in their secondary actions. Shi Wei also clears Lung Heat, cools Blood, and stops bleeding, making it better suited when urinary problems coexist with coughing or with bleeding (blood lin, uterine bleeding). Hai Jin Sha is more specifically focused on clearing heat and unblocking painful urination and stone lin, and does not have Shi Wei's respiratory or hemostatic actions.

Shi Wei vs Qu Mai

Both clear Bladder Damp-Heat and promote urination, but Qu Mai (Dianthus) is more draining and has a stronger action of breaking through blood stasis and promoting menstruation. Shi Wei is milder, has a more protective quality due to its sweet taste, and adds Lung Heat-clearing and hemostatic actions. Shi Wei is preferred when bleeding accompanies the urinary complaint; Qu Mai is preferred when stronger drainage and blood-moving action are needed.

Shi Wei vs Bian Xu

Both Bian Xu (Polygonum aviculare) and Shi Wei clear damp-heat and promote urination for lin syndrome. However, Bian Xu is bitter and slightly cold with a stronger action of killing parasites (used for vaginal itching from damp-heat), while Shi Wei's additional actions on the Lungs (clearing Lung Heat, stopping cough) and its hemostatic ability (stopping bleeding) distinguish it. Shi Wei is the better choice when cough or bleeding accompanies urinary symptoms.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Shi Wei

The most common quality problem with Shi Wei is species substitution. The Chinese Pharmacopoeia recognizes only three species (Pyrrosia sheareri, P. lingua, and P. petiolosa), but the following related species are frequently found as adulterants: Beijing Shi Wei (P. davidii), Southwest Shi Wei (P. gralla), Felt Shi Wei (P. subfurfuracea), Rectangular Shi Wei (P. oblong), and Bare Shi Wei (Lemmaphyllum microphyllum). Although these are all Polypodiaceae ferns with similar appearance, they lack the same active compound profile and therapeutic potency. The key distinguishing features of authentic material are: Pyrrosia sheareri has the largest leaves (10-25 cm) with an asymmetric ear-shaped base; P. lingua has medium lance-shaped leaves (8-12 cm) with a symmetric wedge base and neatly arranged spore clusters; P. petiolosa has the smallest leaves (3-8 cm) that curl into tubes when dried. Adulterant species often differ in leaf shape (rectangular rather than lance-shaped), base symmetry, spore distribution pattern, and hair density.

Educational content — always consult a qualified healthcare provider or TCM practitioner before using any herb.

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Shi Wei

Non-toxic

Contraindications

Situations where Shi Wei should not be used or requires extra caution

Caution

Yin deficiency without Damp-Heat. Shi Wei is a cooling, draining herb that clears Damp-Heat from the Bladder. In people with Yin deficiency who lack true Damp-Heat, using this herb may further deplete fluids and worsen dryness.

Caution

Blood deficiency without Blood stasis. Although Shi Wei can stop bleeding through its cooling properties, it should not be used in cases of bleeding due to Blood deficiency or Spleen Qi deficiency that fails to hold Blood, as its cold nature can weaken the Spleen further.

Caution

Pregnancy. Some traditional sources list Shi Wei as contraindicated in pregnancy due to its cold nature and diuretic properties, which may affect fluid balance. Use only under practitioner supervision.

Caution

Cold patterns of the Bladder or Kidneys. Because Shi Wei is slightly cold in nature and works primarily by clearing Heat and promoting urination, it is not suitable for urinary conditions caused by Cold or Yang deficiency of the Kidneys.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Shi Wei should be used with caution during pregnancy. Some traditional sources explicitly list it as contraindicated in pregnancy (孕妇禁服), likely due to its cold nature, diuretic action, and potential to affect fluid balance. Its strong draining and diuretic properties could theoretically disrupt the body's fluid equilibrium during pregnancy. However, the Ben Jing Feng Yuan notes it was historically used for pregnancy-related urinary retention (妊娠转胞) when combined with Che Qian Zi (Plantago seed), suggesting limited use under expert guidance is possible. As a precaution, avoid use during pregnancy unless specifically prescribed by an experienced practitioner.

Breastfeeding

No specific contraindication for breastfeeding has been established in classical or modern texts. However, Shi Wei's slightly cold nature and diuretic properties mean it should be used cautiously during breastfeeding. Excessive use of cold, draining herbs could theoretically reduce breast milk production by depleting fluids. Use at standard doses for short durations under practitioner guidance is generally considered acceptable.

Children

Shi Wei can be used in pediatric cases with appropriate dosage reduction. Historical records suggest for childhood asthma: children aged 4-9 years, approximately 15g of the whole herb daily; ages 10-15, approximately 30g daily. These are maximum clinical doses for specific conditions and should not be used as general pediatric dosing. For standard use, reduce the adult dose proportionally to the child's age and weight. The herb is relatively mild and non-toxic, making it suitable for children when there is a clear indication of Damp-Heat in the Bladder or Lung Heat with cough.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Shi Wei

No well-documented drug interactions specific to Shi Wei have been established in the pharmacological literature. However, based on its known chemical constituents and pharmacological properties, the following theoretical considerations apply:

Diuretic medications: Shi Wei has documented diuretic effects. Concurrent use with pharmaceutical diuretics (such as furosemide or hydrochlorothiazide) could theoretically potentiate fluid loss and electrolyte imbalance.
Anticoagulant and antiplatelet drugs: Shi Wei contains quercetin and kaempferol, flavonoids that have mild antiplatelet activity in laboratory studies. While clinically significant interactions have not been reported, caution is advisable when combining with warfarin or other blood thinners.
Lithium: As with any herb that significantly increases urine output, Shi Wei could theoretically affect lithium clearance and alter serum lithium levels.

Dietary Advice

Foods and dietary considerations when taking Shi Wei

Because Shi Wei is used primarily for Damp-Heat conditions of the Bladder, it is helpful to avoid greasy, fried, and spicy foods while taking this herb, as these can generate more Heat and Dampness. Alcohol should also be avoided as it produces Damp-Heat. Drinking adequate water supports Shi Wei's diuretic action. Cold and raw foods should be consumed in moderation to avoid weakening the Spleen, which could worsen fluid metabolism.

Botanical Description

Physical characteristics and morphology of the Shi Wei source plant

Shi Wei (Pyrrosiae Folium) comes from several species of Pyrrosia, an epiphytic fern in the Polypodiaceae family. The three official species in the Chinese Pharmacopoeia are Pyrrosia sheareri (Lushan Shi Wei), Pyrrosia lingua (Shi Wei), and Pyrrosia petiolosa (You Bing Shi Wei).

Pyrrosia lingua, the most commonly recognized species, is a medium-sized evergreen fern that can reach up to 30 cm tall. It has a long, slender, creeping rhizome covered in lance-shaped brownish scales. The simple, undivided fronds are upright and leathery, lance-shaped to oval, with olive-green upper surfaces and distinctive felted cinnamon to tan undersides covered in stellate (star-shaped) hairs. When mature, the undersides bear dense, nearly elliptical clusters of sporangia that appear as reddish-brown dots. The plant grows as an epiphyte on rocks and tree trunks in low-altitude forests, at elevations of 100 to 1800 metres. It is native to China, Japan, Korea, Vietnam, and India.

Pyrrosia sheareri (Lushan Shi Wei) is the largest of the three, with fronds 10 to 25 cm long and 3 to 5 cm wide, featuring an asymmetric ear-shaped base. Pyrrosia petiolosa (You Bing Shi Wei) is the smallest, with fronds only 3 to 8 cm long, characteristically curling into a tube shape when dried.

Sourcing & Harvesting

Where Shi Wei is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Can be harvested year-round (all four seasons). Traditionally, the second and seventh lunar months were considered optimal harvest times. The leaves are collected after removing the rhizome and roots, then shade-dried or sun-dried.

Primary growing regions

Shi Wei is widely distributed across China, particularly south of the Yangtze River. The main producing regions are Zhejiang, Hubei, Anhui, Henan, Hebei, and Jiangsu provinces. Historically, the classical 'terroir' (dao di) production area was the Lianyungang area in Jiangsu province. In modern times, Anhui and Zhejiang are the main producing areas for Pyrrosia sheareri (the large-leaf variety considered highest quality), Fujian and Taiwan for Pyrrosia lingua, and Guizhou and Hubei for Pyrrosia petiolosa. The herb also grows in Shandong, Liaoning, Guangxi, Jiangxi, Fujian, Yunnan, Guizhou, Sichuan, Shaanxi, Shanxi, and other provinces. It is also found wild in Japan, Korea, Vietnam, and India.

Quality indicators

Good quality Shi Wei is distinguished by large, thick, intact leaves with a yellowish-green color. For Lushan Shi Wei (Pyrrosia sheareri), the best material has large, thick leaves that are complete and undamaged, with dense reddish-brown stellate hairs on the underside and clearly visible brownish spore clusters between the lateral veins. For the small-leaf varieties, look for thick, neat, clean leaves. The texture should be leathery and firm. The aroma is faint, and the taste should be slightly astringent and bitter. Reject material that is heavily fragmented, discolored to dark brown, or has the star-shaped hairs largely rubbed off. The dried herb should not feel papery thin or overly brittle.

Classical Texts

Key passages from the classical Chinese medical texts that describe Shi Wei and its therapeutic uses

Shen Nong Ben Cao Jing (《神农本草经》)

Chinese: 主劳热邪气，五癃闭不通，利小便水道。

English: It governs consumptive Heat and pathogenic Qi, the five types of urinary retention and obstruction, and promotes the urinary water passages.

Ming Yi Bie Lu (《名医别录》)

Chinese: 止烦下气，通膀胱满，补五劳，安五藏，去恶风，益精气。

English: It stops restlessness, directs Qi downward, opens Bladder fullness, supplements the five types of exhaustion, calms the five Zang organs, dispels pathogenic Wind, and benefits essence and Qi.

Ben Cao Chong Yuan (《本草崇原》)

Chinese: 石韦助肺肾之精气，上下相交，水精上濡，则上窍外窍皆通，肺气下化，则水道行而小便利矣。

English: Shi Wei assists the essential Qi of the Lungs and Kidneys, promoting their mutual interaction above and below. When the water essence ascends and moistens, all the upper and outer orifices open freely. When the Lung Qi descends and transforms, the water passages flow and urination becomes smooth.

Ben Jing Feng Yuan (《本经逢原》)

Chinese: 石韦，其性寒利，故《本经》治劳热邪气，指劳力伤津，癃闭不通之热邪而言，非虚劳之谓。

English: Shi Wei has a cold and disinhibiting nature. Therefore, when the Ben Jing says it treats consumptive Heat and pathogenic Qi, this refers to the Heat pathogen from overexertion that damages fluids and causes urinary obstruction, not to consumptive deficiency.

Historical Context

The history and evolution of Shi Wei's use in Chinese medicine over the centuries

Shi Wei (石韦) was first recorded in the Shen Nong Ben Cao Jing, placing it among the oldest documented Chinese medicinal herbs. The name literally means 'stone leather' or 'stone hide,' referring to its tough, leathery fronds that grow on rocks. The Ming Yi Bie Lu records the famous quality criterion: herbs growing on rocks in mountain valleys of Huayin that "cannot hear the sound of water or people" are considered the best, suggesting that specimens from quiet, undisturbed rocky habitats were prized.

The botanical identity of Shi Wei evolved over time. A 2024 textual study in the Chinese Journal of Experimental Traditional Medical Formulae traced the shifting species sources: before the Song and Yuan dynasties, the primary species used was Pyrrosia petiolosa. During the Ming dynasty, both P. petiolosa and P. sheareri were used. From the Qing dynasty to the present, all three species now listed in the Chinese Pharmacopoeia (P. sheareri, P. petiolosa, and P. lingua) came into mainstream use. The genus name Pyrrosia, meaning 'red,' was given by American botanist Oliver Atkins Farwell in 1931, referring to the reddish appearance of the spore-bearing leaf undersides.

Clinically, the Chang Sha Yao Jie noted that Shi Wei appears in the famous Bie Jia Jian Wan (Turtle Shell Decoction Pill) from Zhang Zhongjing's Jin Gui Yao Lue, used for treating chronic malaria that has formed abdominal masses, leveraging Shi Wei's ability to drain water and dispel stasis. Historically, practitioners distinguished "Great Shi Wei" (large-leaf, mainly P. sheareri, used more for bronchitis) from "Little Shi Wei" (small-leaf species, used more for kidney and urinary conditions), a distinction that continues in modern clinical practice.

Modern Research

3 published studies investigating the pharmacological effects or clinical outcomes of Shi Wei

Network Pharmacology and In Vivo Experimental Study on Pyrrosia lingua for Nephrolithiasis (2022)

Zhang Y et al., Phytomedicine, 2022, Volume 99, 153998

This study investigated how Pyrrosia lingua treats kidney stones using network pharmacology combined with animal experiments. In rat models, high-dose Pyrrosia lingua powder reduced oxalic acid levels and oxidative damage. The active compounds quercetin and kaempferol were found to mediate the toll-like receptor signaling pathway. Importantly, the herb regulated gut microbiota composition and oxalate metabolism enzymes, providing a new mechanistic explanation for its traditional use against urinary stones.

PubMed

Comparative Chemical Profiling of Three Pyrrosia Species by HPLC-DAD with Multivariate Analysis (2018)

Chen S et al., Molecules, 2018, Volume 23, Article 1079

This analytical study compared the chemical profiles of all three official Pyrrosia species used as Shi Wei. Using HPLC analysis of five marker compounds (chlorogenic acid, mangiferin, isomangiferin, trifolin, and astragalin), the study successfully distinguished the three species using multivariate statistical methods. The findings confirmed that different species have distinct chemical compositions, supporting the traditional clinical distinction between 'Great Shi Wei' (P. sheareri, used for bronchitis) and 'Little Shi Wei' (P. lingua and P. petiolosa, used for nephritis).

PubMed

Isolation of a New Xanthone Glycoside from Pyrrosia sheareri (2019)

Not fully available from search results

This phytochemistry study isolated a new xanthone glycoside (3,5,7,8-tetramethoxyxanthone-1-O-beta-D-glucopyranoside) along with five known compounds (mangiferin, kaempferol, quercetin, chlorogenic acid, and diploptene) from the whole plant of Pyrrosia sheareri. The study contributes to understanding the chemical basis of Shi Wei's medicinal properties.

PubMed

Research on individual TCM herbs is growing but still limited by Western clinical trial standards. These studies provide emerging evidence and should be considered alongside practitioner expertise.