Giant Knotweed Rhizome
Hu Zhang (Rhizoma Polygoni Cuspidati)——Ming Yi Bie Lu (Miscellaneous Records of Famous physicians)
The Processing of Giant Knotweed Rhizome
The root of perennial herbaceous plant Polygonum cuspidatum Sieb. et Zucc.
Most areas of China.
Collected in spring and autumn.
The true smell and taste
Slight smell, stightly bitter and astringent.
Thick, without internal hollow.
The Effect of Giant Knotweed Rhizome
Bitter and cold; liver, gallbladder and lung meridians entered.
Excrete dampness and remove jaundice, clear heat and remove toxicity, resolve blood stasis and stop pain, resolve phlegm and relieve cough.
A. Jaundice of damp-heat type, stranguria
It is good at clearing damp-heat from liver and gallbladder and inducing diuresis, so it is the essential herb for jaundice of damp-heat type. It can be decocted alone or combined with other herbs such as Yin Chen Hao, Huang Bai and Zhi Zi to strengthen the actions of clearing damp-heat and alleviating jaundice. For stranguria due to damp-heat accumulation in bladder manifested as difficult and painful urination, it can be used alone or combined with the diuresis-inducing and stranguria-treating herbs such as Mu Tong, Che Qian Zi and Qu Mai to mutually strengthen. It is also indicated for leukorrhagia of damp-heat type for its actions of clearing heat and excreting dampness. It is usually combined with the heat-clearing, damp-removing and leucorrhagia-stopping herbs such as Huang Bai, Bi Xie and Qian Shi.
B. Scald, carbuncle, swelling and sore
It has the actions of cooling blood, clearing heat and removing toxicity, activating blood and alleviating pain. For scald, it is usually used alone or combined with Di Yu and Bing Pian for external application. It or they can be ground into powder for local application or mixed with oil for external application. Its or their decoction can also be used for local application. For carbuncle, swelling and sore due to damp-heat accumulation, it can be decocted for washing or smashed for local application. To strengthen the action, it can also be decocted with the heat-clearing and toxicity-removing herbs such as Pu Gong Ying, Jin Yin Hua and Lian Qiao for oral taking.
C. Amenorrhea dysmenorrhea, mass, trauma and arthralgia of wind-damp type
It has the actions of activating blood and resolving blood stasis to alleviate pain. It is indicated for all syndromes due to blood stasis. For amenorrhea and dysmenorrhea due to blood stasis, it is usually combined with the herbs of activating blood and inducing menstruation to alleviate pain such as Tao Ren, Yan Hu Suo and Hong Hua. For mass, it is usually combined with the blood-breaking and mass-eliminating herbs such as San Leng and E Zhu. For pain due to trauma, it is usually combined with Dang Gui, Ru Xiang and Mo Yao to strengthen the actions of activating blood, relieving swelling and alleviating pain.
It is also indicated for chronic arthralgia due to qi and blood stagnation and transforming into heat manifested as redness, swelling and pain of joints, because it has the actions of draining damp, activating blood and unblocking meridians to stop pain. It can be used alone for decocting or dunking into wine, or combined with the wind-damp-dispelling herbs such as Fang Feng, Qin Jiao and Fang Ji.
D. Cough due to lung heat
It has the actions of purging heat, resolving phlegm and stopping cough. It is especially good for cough due to lung heat. It can be decocted alone or combined with Bei Mu, Pi Pa Ye and Xing Ren to strengthen the actions of clearing lung heat and resolving phlegm to stop cough.
Additionally, it also has the actions of purging heat and promoting defecation, cooling blood and stopping bleeding. It is also indicated for constipation due to heat accumulation, hematemesis, hematochezia and hemorrhoids with bleeding.
Dosage and Administrations
Decoct 9~15g. Proper dosage is for external application. It can be externally used by washing with its decoction, or be ground into powder for local application, or be prepared as ointment for local application.
It is contraindicated for pregnant women.