Japanese blood grass, as its name implies, seemingly relates to blood. But how come this lovely ornamental plant gets such a strange name like that? The reasons are two-fold. The first evidence that might come to mind is its distinct reddish foliage, which looks like blood in color at the tips though it is green in youth. Another one comes from its medicinal property – it is true that Japanese bloodgrass root, also known as Bai Mao Gen, is commonly used to stop the bleeding in Chinese herbal remedies.
What is Japanese blood grass or imperata cylindrica?
Commonly known as Imperata Cylindrica, it refers to the root of a species in the genus Imperata. And some other names for this herb include cogon grass, wolly grass, blady grass, Bai Mao, and kunai grass, etc. It is a perennial grass, which is native to northern Africa, Turkey, Iraq, Central Asia, Caucasus, and Mediterranean. The type specimen comes from southern France. In China, it grows in northern parts like Henan, Liaoning, Shanxi, Shandong, and Xinjiang provinces. And it is found mostly in meadows out on the road, hillsides, seaside, and sandiness grassland, etc.
Japanese blood grass has densely scaly rhizome, erect fascicular stalk, 30 to 90cm in height, and 4 to 10mm pubescence at the nodes. The rhizome is in long cylindrical shape, branching sometimes, 30 to 60cm long at different lengths, and 2 to 4mm in diameter. The surface is yellowish-white or faint yellow in color, lustrous, with vertical wrinkles, obvious nodes with remnant gray-brown scale leaves and radicula, and 1 to 3cm between nodes. It is light and tough in texture. The fibroid transverse section is yellowish-white in color, mostly with radial crevices, sometimes a pinhole seen at the center. It is slightly odorous and slightly sweet in taste.
From the medicinal herb point of view, those preferred are larger in shape, white in color, and sweeter in taste. The medicinal imperata cylindrica is collected during spring and autumn, overground part and scaly sheath removed, washed clean, used in fresh form or dried in the sun in bundles.
What is it used for in TCM?
From the perspective of Traditional Chinese Medicine (TCM), it is cold and sweet in nature and goes to a few of meridians such as lung, stomach, small intestine, and urinary bladder.
Main functions are to cool blood, stop bleeding, promote the secretion of saliva or body fluid, clear heat, promote urination and treat stranguria. Main uses and indications are fidget and thirst in febrile diseases, vomiting blood due to excessive heat, coughing up blood, nosebleed, short of breath caused by lung heat, hiccup due to stomach heat, uterine bleeding, purpura, stranguria, edema, and jaundice, etc.
Usual dosage is from 9 to 24 grams.
Bai Mao Gen related Chinese herbal formulas
(1). Shi Hui San, from Shi Yao Shen Shu (A Miraculous Book on Ten Recipes), is mainly for bleeding at upper part of human body, which is caused by the rampageous blood derailed out of the track of meridians caused by uprush of blazing heat and Qi. Other individual herbs in this formula include Da Ji (Japanese Thistle, Cirsium), Xiao Ji (Small Thistle), He Ye (Lotus Leaf), Ce Bai Ye (Biota Leaves), Qian Cao Gen (Rubia Root), Zhi Zi (Cape Jasmine Fruit, Gardenia), Da Huang (Rhubarb Root), Mu Dan Pi (Tree Peony Root Cortex), and Zong Lu Pi (Trachycarpus Stipule Fiber).
(2). Mao Gen Yin Zi, from Wai Tai Mi Yao (Arcane Essentials from the Imperial Library), is formulated for hematuria due to heat in womb. Other herbs in this formula are Fu Ling (Poria, China Root), Ren Shen (Ginseng Root), and Shu Di Huang (Rehmannia, Chinese Foxglove Root).
(3). Mao Lu Gen Jian, from Yao Wu Yu Fang Ji (Herbs and Formulas), is used for vomit caused by febrile diseases, gastrointestinal bleeding, hematuria, and uropenia in edema. The other herb is Xian Lu Gen (Fresh Reed Rhizome).
Proven remedies tips
(1). It should avoid ironwork and sliced one should not soak in water just in case of sylvine loss;
(2). Clinically it can be used alone or accompanied with herbs like Da Ji (Japanese Thistle, Cirsium), Xiao Ji (Small Thistle), Zhi Zi (Cape Jasmine Fruit, Gardenia), Ce Bai Ye (Biota Leaves), and Mu Dan Pi (Tree Peony Root Cortex) to enhance the effects of cooling and stopping bleeding;
(3). For thirst due to body fluid impairment in febrile diseases, it is all right to use the fresh herb in some mild cases while in severe cases other herbs, like Xian Shi Hu (Fresh Dendrobium Stem), Tian Hua Fen (Trichosanthes Root), and Xian Lu Gen (Fresh Reed Rhizome), need to be added to reinforce the functions of clearing heat and relieving thirsty by promoting the secretion of saliva or body fluid;
(4). For hot painful and difficult urination caused by heat accumulated in bladder, it is better to use along with herbs like Shi Wei (Pyrrosia leaves), Dong Kui Zi (Musk Mallow Seeds), and Hua Shi (Talcum Powder).
Possible side effects and contraindications
According to the research conducted by The American Herbal Products Association, the result reveals that it is a safe herb to consume so that it is rated into the Class A category. From TCM considerations, due to its cold property Japanese blood grass (Bai Mao Gen) should not be used for those people suffering from diarrhea or loose stools caused by deficiency of spleen and stomach.