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Prostrate Knotweed

What is Prostrate Knotweed?

Prostrate Knotweed (bian xu, 篇蓄), also known as Herba Polygoni Avicularis or Common Knotgrass Herb, refers to the aerial part of Polygonum aviculare L., an annual herbaceous plant that belongs to the Dolygonaceae family. 

In China, Prostrate Knotweed is found in provinces such as Henan, Sichuan, Zhejiang, Shandong, Jilin and Hubei.

In Traditional Chinese Medicine (TCM), Prostrate Knotweed falls under the category of ‘Herbs that drain Dampness’. Such herbs are typically diuretics that can promote the increased production of urine in order to remove Dampness that has accumulated in the body’. 

Cool in nature, Prostrate Knotweed can help individuals with too much Heat in their body, such as those experiencing a yang excess or a yin deficiency, to restore a harmonious yin-yang balance. Bitter and sweet in taste, Prostrate Knotweed can cleanse the body by clearing Heat, drying Dampness and promoting elimination via urination or bowel movements. 

Also, Prostrate Knotweed can slow down acute reactions, detoxify the body and has a tonic effect because they replenish qi and blood. In particular, Prostrate Knotweed targets the bladder.

Functions and Benefits of Prostrate Knotweed

Traditional Chinese Medicine (TCM) shows that Prostrate Knotweed has the following health benefits.

Prostrate Knotweed can clear Damp-Heat in the lower energizer, and induce diuresis to treat symptoms such as stranguria. This herb is often indicated for urolithic stranguria and stranguria caused by Heat. To treat blood stranguria, Prostrate Knotweed can be combined with other blood-Heat-clearing or bleeding-stopping herbs.    

Also, Prostrate Knotweed can remove Damp-Heat to relieve itching and expel parasites. It is used to treat intestinal parasites such as tapeworm, hookworm and pinworm. This herb is also indicated for vulva pruritus, eczema, and damp-sore caused by the accumulation of Damp-Heat in the lower energizer. 

Prostrate Knotweed can be used singly or combined with other herbs to be used as an external wash too. In addition, Prostrate Knotweed is indicated for jaundice caused by Damp-Heat too.

How to Use Prostrate Knotweed

The recommended daily dosage of Prostrate Knotweed is 9 – 15g, when used as a decoction. When using Prostrate Knotweed in its raw form, the dosage may be doubled.

If you are using Prostrate Knotweed for external application, do consult your healthcare provider on the appropriate dosage to be used for your condition.

Prostrate Knotweed and its supplements may be found in herbal stores and Asian specialty markets.

Cautions and Side Effects of Prostrate Knotweed

Prostrate Knotweed should not be used by individuals experiencing qi deficiency, weak digestive systems or difficult urination caused by abdominal weakness.

Do note that Prostrate Knotweed may cause side effects such as dermatitis or gastrointestinal disturbance. Over-consumption of Prostrate Knotweed may cause depletion of essence (jing).

Prostrate Knotweed should not be used together with diuretics such as chlorothiazide or hydrochlorothiazide.

We strongly encourage you to consult your healthcare provider before deciding to add Prostrate Knotweed to your healthcare routine!


Here is a summary for Prostrate Knotweed:

  • Herb name (Chinese): 篇蓄
  • Herb name (Pin Yin): biǎn xù
  • Herb name (English): Common Knotgrass Herb
  • Herb name (Botanical): Herba Polygoni Avicularis
  • Origin of species: Polygonum aviculare L.
  • Part(s) of herb used: Aerial part of plant
  • Geo-specific habitat(s): Henan, Sichuan, Zhejiang, Shandong, Jilin, Hebei
  • Taste(s) & Properties: Bitter; Slightly cold; Administrates the Bladder meridian
  • Actions: Eases difficult and painful urination; Relieves skin rashes or itchiness

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