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Cogongrass rhizomes

Chinese: 白茅根

Pinyin: Bái Máo Gēn

Parts used: Dried rhizome

TCM category: Herbs that stop bleeding

TCM nature: Cold

TCM taste(s): Sweet

Organ affinity: Bladder Lung Stomach

Scientific name: Imperata cylindrica

Other names: Kunai grass, Blady grass, Alang-alang, Lalang grass, Cotton wool grass, Kura-kura, Speargrass, Woolly grass

Use of cogongrass rhizomes (Bai Mao 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: Wash, moisten, cut and dry

Dosage: 10 - 30 grams

Main actions according to TCM*: Stops bleeding due to Heat in the Blood. Drains Heat and encourages urination. Relieves Heat in the Stomach and Lungs.

Primary conditions or symptoms for which cogongrass rhizomes may be prescribed by TCM doctors*: Hematemesis Nosebleed Hematuria Acute nephritis Dysuria Edema

Contraindications*: This herb should not be used where there is Cold associated with Spleen Deficiency.

Key TCM concepts behind cogongrass rhizomes (Bai Mao Gen)'s properties

In Traditional Chinese Medicine (TCM), cogongrass rhizomes are plants that belong to the 'Herbs that stop bleeding' category. Like the name indicates these herbs tend to have hemostatic properties, meaning that they help stop various types of hemorrhages and echymosis. Unlike other herbs they often tend to be used externally.

Furthermore cogongrass rhizomes are plants that are Cold in nature. This means that cogongrass 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 cogongrass rhizomes can help restore a harmonious balance between Yin and Yang.

Cogongrass 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 cogongrass 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 cogongrass rhizomes are thought to target the Bladder, the Lung and the Stomach. 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. 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.

Research on cogongrass rhizomes (Bai Mao Gen)

Shufeng Liangxue Decoction (consisting of imperata rhizome) is effective and safe in treating hormone dependence dermatitis, with the efficacy better and relapse rate lower than those of treatment with Western medicine alone.1


1. Bai YS, Zhou CY, Wang JQ. (2008). Clinical observation on auxiliary treatment of hormone dependence dermatitis by shufeng liangxue decoction. Zhongguo Zhong Xi Yi Jie He Za Zhi. , 28(12):1121-3.

Use of cogongrass rhizomes (Bai Mao Gen) as food

Cogongrass rhizomes are also eaten as food.