English Name: phragmites root, reed rhizome
Pharmaceutical Name: Rhizoma Phragmatis
Medica Category: Heat-Clearing and Fire-Purging Herbs
Properties: Lu Gen enters the Lung and Stomach channels; it is sweet in nature and cold in temperature.
The Chinese Herb Lu Gen is the dried root of phragmites, one of four species of hollow-stemmed, aquatic grasses in the phragmites genus that can grow to well over the height of a standing person. Once harvested, the phragmites roots are stripped of fibrous material, cut into pieces and sun-dried for use as medicine.
Lu Gen clears heat and generates fluids in the Lungs. It is used when excess heat damages the fluids and Lung Yin (presenting as cough with scanty, yellow sputum and dry mouth and throat). Lu Gen also re-regulates rising Lung qi (i.e. alleviates cough) when excess heat is the cause.
Lu Gen is used in wind-heat release formulas San Ju Yin and Yin Qiao to moisten the Lungs and alleviate thirst.
Lu Gen clears stomach heat to re-regulate Stomach qi when excess heat causes its reversal (i.e. nausea and vomiting).
–additional comments (clinical):
Xian Lu Gen is the fresh juice of the phragmites rhizome. It is cool and sweet in nature and is more effective than the dried reed at cooling heat and generating fluids. It is used when heat from a warm pathogen causes Wei or Qi level disorders; it is also used to clear residual/lingering heat from febrile disorders when there is thirst due to damaged yin (source: American Dragon).