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Common reed rhizomes

Chinese: 芦根

Pinyin: Lú Gēn

Parts used: Fresh or dried rhizome

TCM category: Herbs that clear Heat and purge Fire and/or clear Summer Heat

TCM nature: Cold

TCM taste(s): Sweet

Organ affinity: Stomach Lung

Scientific name: Phragmites communis

Other names: Wei Jing

Use of common reed rhizomes (Lu Gen) 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: Remove impurities and fibrous roots, wash, moisten slightly, cut into sections, and dry. If using fresh you can bury it in wet sand to prevent dryness.

Dosage: 9 - 30 grams

Main actions according to TCM*: Clears Heat and promotes the generation of Fluids. Dispels Lung Heat. Dispels Stomach Heat. Promotes urination and clears Heat in the urinary tract. Calm the minds and stop vomiting.

Primary conditions or symptoms for which common reed rhizomes may be prescribed by TCM doctors*: Dehydration Phlegm Vomiting Strangury Lung abscess

Contraindications*: This herb should not be used when there is weakness in the Spleen and Stomach caused by Cold.

Common TCM formulas in which common reed rhizomes (Lu Gen) are used*

Wei Jing Tang

Source date: 627 AD

Number of ingredients: 4 herbs

Formula key actions: Clears heat from the Lungs. Transforms Phlegm. Drives out Blood-Stagnation. Discharges pus.

Conditions targeted*: BronchitisBronchiectasis and others

Lu Gen is a king ingredient in Wei Jing Tang. Like the name indicates, it means it has more power than other ingredients in the formula.

In Wei Jing Tang, Lu Gen clears Heat from the Lungs.  In Encountering the Sources of the Classic of Materia Medica, the 17th-century physician Zhang Lu wrote that it "specializes in facilitating passage through the orifices and thus is good at treating Lung abscess."

Read more about Wei Jing Tang

Key TCM concepts behind common reed rhizomes (Lu Gen)'s properties

In Traditional Chinese Medicine (TCM), common reed rhizomes are plants that belong to the 'Herbs that clear Heat and purge Fire and/or clear Summer Heat' category. Herbs in this category are used to clear inflammatory and infectious conditions, referred to as 'Internal Heat' in TCM. This is why most of the herbs in this category will have both antibacterial and antiviral properties. In TCM one has too much 'Internal Heat' in their body as a result of a deficiency of 'Yin' (which is Cold in nature, see our explanation on Yin and Yang) or, more commonly, an Excess of Yang (Hot in nature). Herbs that clear Heat and purge Fire treat the latter and as such tend to be Cold or Neutral in nature.

As suggested by its category common reed rhizomes are plants that are Cold in nature. This means that common reed rhizomes typically help people who have too much 'Heat' in their body. 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 common reed rhizomes can help restore a harmonious balance between Yin and Yang.

Common reed rhizomes also taste 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. Sweet ingredients like common reed rhizomes 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 common reed rhizomes are thought to target the Stomach and the Lung. In TCM the Stomach is responsible for receiving and ripening ingested food and fluids. It is also tasked with descending the digested elements downwards to the Small Intestine. 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.

Use of common reed rhizomes (Lu Gen) as food

Common reed rhizomes are also eaten as food.