Biǎn Xù (萹蓄), known in English as Knotgrass (Polygonum aviculare), is a cool, bitter Chinese herb from the Drain damp category. It enters the Bladder channel. Its main action: promotes urination, relieves painful urinary dysfunction.
| Pinyin | Biǎn Xù (Bian Xu) |
|---|---|
| Chinese | 萹蓄 |
| English | Knotgrass |
| Botanical name | Polygonum aviculare |
| Category | Drain damp |
| Nature | Cool |
| Flavour | Bitter |
| Channels | Bladder |
| Dosage | 9–15g |
| Cautions | Spleen deficiency; no Damp-Heat |
Actions
- Promotes urination, relieves painful urinary dysfunction
- Kills parasites, stops itching
Indications
- Heat painful urinary dysfunction with scanty dark urine
- Abdominal pain from parasites
- Eczema, vaginal itching and discharge (topical wash)
How to remember Biǎn Xù
Drain damp herbs are mostly cool or cold and sweet, and most enter the Bladder channel.
- You can work these out
- Cool: like most Drain damp herbs
- Bladder channel: from its action “Promotes urination”
- Learn by heart
- Bitter: unusual for Drain damp herbs (most are sweet)
Formulas containing Biǎn Xù
Other Drain damp herbs
- Fú Líng
- Yì Yǐ Rén
- Zé Xiè
- Mù Tōng
- Huá Shí
- Chē Qián Zǐ
- Qú Mài
- Bì Xiè
- Yīn Chén Hāo
- Jīn Qián Cǎo
- Hǎi Jīn Shā
- Zhū Líng
- Dēng Xīn Cǎo
- Tōng Cǎo
- Shí Wéi
- Dōng Kuí Zǐ
- Dì Fū Zǐ
- Dōng Guā Zǐ
Test yourself
What is the nature and flavour of Biǎn Xù?
Biǎn Xù is cool and bitter.
Which channels does Biǎn Xù enter?
Biǎn Xù enters the Bladder channel.
What are the actions of Biǎn Xù?
Promotes urination, relieves painful urinary dysfunction; Kills parasites, stops itching.
What is Biǎn Xù used for?
Heat painful urinary dysfunction with scanty dark urine; abdominal pain from parasites; eczema, vaginal itching and discharge (topical wash).
Which formulas contain Biǎn Xù?
Bā Zhèng Sǎn.
Practise Biǎn Xù and the other 290 herbs
Recognise each herb from its picture, recall its nature, flavour, channels and actions, and review it again just before you would forget it.
Try the 5-question herb quizShen Study is a study tool. Doses and cautions are as taught in standard Chinese materia medica texts; they are not prescribing advice.