Imperata Rhizome, a traditional Chinese medicine, is the dried rhizome of Imperata cylindrica Beauv. var. major (Nees) C.E. Hubb., a plant belonging to the genus Imperata in the Poaceae family. This herb has the therapeutic effects of cooling the blood and stopping bleeding, clearing heat and promoting diuresis, and clearing heat from the lungs and stomach.It is primarily used to treat hemoptysis and epistaxis due to blood heat, hematuria, thirst and restlessness in febrile diseases, damp-heat jaundice, edema with oliguria, painful and scanty urination due to heat, vomiting caused by stomach heat, and cough caused by lung heat.
White Reed Root
Imperata Rhizome, a traditional Chinese medicine, is the dried rhizome of Imperata cylindrica Beauv. var. major (Nees) C.E. Hubb., a plant belonging to the genus Imperata in the Poaceae family. This herb has the therapeutic effects of cooling the blood and stopping bleeding, clearing heat and promoting diuresis, and clearing heat from the lungs and stomach.It is primarily used to treat hemoptysis and epistaxis due to blood heat, hematuria, thirst and restlessness in febrile diseases, damp-heat jaundice, edema with oliguria, painful and scanty urination due to heat, vomiting caused by stomach heat, and cough caused by lung heat.
Chinese Name : 白茅根
Latin Name : Imperatae Rhizoma
Aliases : Mao Gen, Lan Gen, Ru Gen, Di Juan, Di Jin, Jian Du, Bai Mao Juan, Bai Hua Mao Gen, Si Mao, Wan Gen Cao, Mao Cao Gen, Di Jie Gen, Jian Cao Gen, Tian Cao Gen, Si Mao Cao Gen, Han Cao Gen
Authentic Producing Area : Found throughout the country, but more abundant in North China
Nature, Flavor & Meridian Tropism : Cold in nature, sweet in taste; enters the Lung, Stomach, and Bladder meridians
Benefits & Efficacy
Benefits
1. Cools the blood and stops bleeding; clears heat and promotes diuresis. (Reference: *Pharmacopoeia of the People’s Republic of China, 2020 Edition*; *Clinical Guidelines for the Use of Medicinal Herbs, Volume on Sliced Chinese Herbal Medicines, 2020 Edition*) 2. Clears heat from the Lung and Stomach meridians. (Reference: *Chinese Materia Medica: For Traditional Chinese Medicine Majors, New Century, 2nd Edition*)
Indications
Mainly used for blood-heat-induced hematemesis, epistaxis, hematuria, thirst and restlessness in febrile diseases, damp-heat jaundice, edema with oliguria, painful and scanty urination due to heat, vomiting due to stomach heat, and cough due to lung heat.
Usage and Dosage
1. Internal use: Decoct 9–30 g (or 30–60 g of fresh material); or pound to extract juice. 2. External use: Apply an appropriate amount of fresh material, pounded to extract juice.
Precautions
Contraindicated in cases of spleen-stomach deficiency-cold with frequent urination but no thirst.
Chemical Constituents
This herb primarily contains triterpenoid compounds (such as luzhusu, baimaosu, yinbaimaosu, yiyisu, fernsene, simiduanosu, and isoshanzhitriol) and lactone compounds (such as baitoongsu). Additionally, it contains organic acids, sterols, and carbohydrates.
Pharmacological Actions
This product has hemostatic, anti-inflammatory, immune-boosting, and diuretic effects.
Relevant Discussions
1. *Shennong’s Classic of Materia Medica*: “It treats exhaustion, weakness, and emaciation; tonifies the middle and boosts qi; removes blood stasis and amenorrhea; alleviates fever and chills; and promotes bowel movements.”
2. *Ben Cao Zheng Yi*: “White茅根 is cold in nature and very sweet in taste; it can clear heat from the blood without causing dryness, nor is it sticky or greasy. Therefore, it cools the blood without risk of causing blood stasis, and is primarily used to treat vomiting of blood and epistaxis.”
3. *Yi Xue Zhong Zhong Can Xi Lu*: “It excels at dispersing stagnant heat in the viscera and expelling the toxins of measles and rashes outward;it is also effective for promoting urination in cases of dysuria accompanied by pain, scanty urine due to heat, abdominal distension, and body swelling; it can also enter the Lung meridian to clear heat, thereby calming coughs and relieving wheezing; because of its sweet taste—and since chewing fresh roots produces abundant saliva—it can enter the Stomach to nourish yin, generate body fluids, and quench thirst, as well as treat heat in the Lung and Stomach manifesting as hemoptysis, hematemesis, epistaxis, and hematuria; however, fresh roots must be used for the effects to be pronounced.”
Applications
Clinical Applications
1. To treat intermittent hematuria caused by deficiency with heat, it is often combined with ginseng, rehmannia, and poria, as in the Maogen Decoction (from *Wai Tai Mi Yao*).
2. To treat damp-heat jaundice, it is often combined with Yinchen and Shanzhi.
3. To treat vomiting caused by stomach heat, it is often used with Kudzu Root, as in the Maogen Decoction (from *Xiaopin Fang*); to treat coughing and wheezing caused by lung heat, it is often combined with Mulberry Bark, as in the Rusheng Decoction (from *Shenghui Fang*).
Related Compatibility
1. White茅根 combined with Plantain Seed: White茅根 cools the blood and stops bleeding, clears heat, and promotes diuresis; Plantain Seed promotes diuresis, relieves dysuria, and clears heat accumulation in the bladder. When combined, these two herbs synergistically enhance each other’s effects, providing effective blood-cooling, hemostatic, heat-clearing, and diuretic benefits. This combination is suitable for treating oliguria, painful urination, and hematuria caused by internal retention of damp-heat or the mutual accumulation of water and heat.
2. White茅根 combined with Gypsum: White茅根 clears heat and generates body fluids, clearing heat from the lungs and stomach; Gypsum clears heat from the lungs and stomach, relieves restlessness, and quenches thirst. When combined, these two herbs clear heat without damaging yin and generate body fluids without impairing stomach function. Together, they achieve the effects of clearing heat, relieving restlessness, generating body fluids, and quenching thirst. This combination is suitable for conditions such as stomach heat with restlessness and thirst, as well as lung heat with coughing and wheezing.
Medicinal Identification
1. Raw White Reed Root and Charred White Reed Root: Raw White Reed Root excels at cooling the blood and stopping bleeding, clearing heat, promoting fluid production, and promoting urination. It is commonly used for blood-heat-induced hemoptysis, epistaxis, hematuria, thirst and restlessness in febrile diseases, damp-heat jaundice, edema with oliguria, and painful and scanty urination due to heat.Charred White Reed Root has an astringent taste and a reduced cold nature; its effects in clearing heat and cooling the blood are milder, while its hemostatic effect is enhanced. It is specifically used for bleeding disorders, with a focus on astringent hemostasis, and is commonly employed in cases of acute bleeding.
2. White Reed Root and Reed Root: Both can clear heat from the lungs and stomach and promote diuresis, treating coughs due to lung heat, vomiting due to stomach heat, and painful, scanty urination; they are often used in combination. However, White Reed Root tends to enter the blood division and excels at cooling the blood and stopping bleeding, so it is frequently used for bleeding conditions caused by uncontrolled blood flow due to blood heat.Reed Root tends to enter the Qi level and excels at clearing heat and purging fire; therefore, it is frequently used for feverish conditions with restlessness and thirst, vomiting due to stomach heat, and coughs caused by lung heat.
3. White Reed Root and Small Thistle: Both can cool the blood and stop bleeding, while also promoting diuresis. They are used to treat various bleeding conditions caused by blood heat, and are particularly effective for hematuria and bloody dysuria.However, White Reed Root also clears heat and promotes diuresis, making it useful for treating edema, painful and scanty urination due to heat, and jaundice; it also clears heat from the lungs and stomach, making it effective for treating vomiting due to stomach heat and coughs due to lung heat. Small Thistle can disperse blood stasis, eliminate toxins, and reduce swelling, making it suitable for treating sores and ulcers caused by heat toxins.
Related Medicines
Urethane Enema Solution, Heat-Clearing Honeysuckle Syrup, Shenning Powder Capsules, Nephritis Tablets, Hemorrhagic Fever Prevention Tablets.
Related Prescriptions
White Maogeng Decoction (*Shengji Zonglu*), Maogeng Decoction (*Wai Tai Mi Yao*), White Maogeng Powder (*Shenghui Fang*), and Rusheng Decoction (*Shenghui Fang*).
Notes
Patients requiring treatment with traditional Chinese medicine should first consult a licensed TCM hospital, where a TCM practitioner will conduct a professional diagnosis and prescribe the appropriate herbal formula.
Processing & Preparation
Harvesting & Processing
Harvest in spring or fall; remove the aerial parts and scaly leaf sheaths, wash thoroughly, and use fresh or tie into bundles to dry in the sun.
Processing Methods
1. Dried White Reed Root: Sort out impurities, wash thoroughly, moisten slightly, cut into sections, sun-dry, and sift to remove debris.
2. Charred White Reed Root: Place sections of white reed root in a wok and stir-fry over high heat until blackened; spray with clean water, remove, and sun-dry.
Storage Methods
Store in a dry container in a well-ventilated, dry place; ensure the charred Maogen is allowed to cool promptly to prevent reignition.
Crude Drug Identification
Identification
1. Cross-section of this product: The epidermal cells form a single layer; they are small and square-shaped, with some containing siliceous bodies. The hypodermis consists of 1–3 layers of fibers with thick, lignified walls.The cortex is relatively broad, containing more than 10 leaf-derived vascular bundles of the limited-external-cork type, often flanked by fissures; the cells of the inner cortex have thickened inner walls, and some contain siliceous bodies. The stele contains numerous scattered vascular bundles of the limited-external-cork type; the vascular bundle sheaths are arranged in annular rows of fibers that are lignified, and the outer vascular bundles form a ring by connecting with the fibers.The center is often hollow. The powder is yellowish-white. Epidermal cells are arranged in parallel rows; each longitudinal row typically consists of one long cell alternating with two short cells, with the long cells having undulating cell walls. Endodermis cells are rectangular, with one side of the cell wall thickened; striations and pore holes are distinct, and the walls contain siliceous bodies. Subepidermal fibers have thick, lignified walls and often possess transverse septa.
2. Take 1 g of the powdered sample, add 20 mL of ether, sonicate for 10 minutes, filter, and evaporate the filtrate to dryness. Dissolve the residue in 1 mL of ether to prepare the test solution. Separately, take 1 g of white reed root reference material and prepare the reference solution using the same method.Test by thin-layer chromatography (General Chapter 0502): Pipette 10 μL of each of the two solutions and apply them separately to the same silica gel G plate. Develop with dichloromethane, remove the plate, allow it to air-dry, and spray with a 10% ethanol solution of sulfuric acid. Heat at 105°C until the spots become clearly visible.In the chromatogram of the test sample, spots of the same color appear at positions corresponding to those in the chromatogram of the reference herbal material.
Properties of Crude Drugs
This product is oblong cylindrical in shape, 30–60 cm long, and 0.2–0.4 cm in diameter. The surface is yellowish-white or pale yellow, slightly lustrous, with longitudinal wrinkles; the nodes are distinct and slightly protruding, and the internodes vary in length, typically ranging from 1.5 to 3 cm.It is light in weight and slightly brittle; the cross-section reveals a white periderm with numerous fissures arranged radially, and a pale yellow central cylinder that separates easily from the periderm. It has a faint odor and a slightly sweet taste.
Properties of Processed Slices
This product consists of cylindrical segments. The outer surface is yellowish-white or pale yellow, with a slight sheen and longitudinal wrinkles; some segments have slightly raised nodes. The cross-section shows a white periderm with numerous fissures arranged radially; the pith is pale yellow or hollow and easily separates from the periderm. It has a faint odor and a slightly sweet taste.
Botanical Information
Botanical Classification
White茅 (Imperata cylindrica), a plant of the genus Imperata in the family Poaceae.
Morphological Characteristics
A perennial herb, 20–100 cm tall. The rhizome is white, creeping and spreading, densely covered with scales. Culms are tufted, erect, cylindrical, smooth, and glabrous. Leaves are linear or linear-lanceolate; basal leaves are nearly as long as the plant; cauline leaves are shorter; leaf sheaths are brown, with short ligules.The panicle is compressed into a spike, terminal, and cylindrical. The caryopses are elliptical and dark brown; when mature, the inflorescence is covered with long, soft white hairs. Flowering occurs from May to June, and fruiting from June to July.
Distribution Area
It is distributed in North China, Northeast China, East China, Central and South China, Southwest China, as well as Shaanxi and Gansu.
Growth Habits
It prefers a warm and humid climate, is sun-loving and drought-tolerant, and is best cultivated on gently sloping or flat land.
Propagation Methods
Propagated by rhizomes.
Cultivation Techniques
Propagation by rhizomes: In spring, dig up the underground rhizomes of white sedge and plant them with a row and plant spacing of 30 cm × 30 cm.