Growing freely in the hillside, in the damp grass by streams, or beneath the woods, wild pinellia (Ban Xia) begins blossoming in May in the lunar calendar. After blossoming, pinellia tuber is grown old enough and ready to be excavated for medicinal purpose. May in the lunar calendar is just the time of midsummer, which is the very reason why its Chinese name comes from.
What is pinellia rhizome?
It is a perennial herb in Araceae, 15 to 35cm high, with tuber nearly in spherical shape, and 0.5 to 3.0cm in diameter. TCM wise, the medicinal part is the tuber, namely Rhizoma Pinelliae Ternatae (Thunb.) Breit.
The dried pinelliae tuber is spherical, semiorbicular, or oblique, 0.8 to 2cm in diameter. Surface is white or light yellow, with yellow spotted residual cortex. The top is mostly round and flattened, with yellowish brown depressed stem scars in the middle and dense brown pit-shape fibril scars around, and underneath is the blunt sleek end. The quality is solid and compact. The kidney-shaped vertical section is pure white and with fine mealiness, but grayish white or with yellow streaks in older ones or in those unfitting the drying process. Medicinally the preferred one is bigger, clean white, solid and with fine mealiness.
What is it used for?
From the perspective of Traditional Chinese Medicine (TCM), it is acrid, warm, and toxic in nature and covers meridians of lung, spleen, and stomach. Main functions are to dry dampness and transform phlegm, descend reversed Qi and stop vomiting, and relieve oppression and resolve hard mass. Main usage and indications are cough and dyspnea due to excessive phlegm, dizziness and palpitation caused by phlegm and fluid retention, wind-phlegm vertigo, headache and coma due to blocking of the respiratory system, nausea and vomiting, distention and fullness in chest, and globus hysteriocus. In addition, externally it is used for swelling and ulcer, pyogenic infections, and venomous snake bite. Usual dosage is 4.5 to 12 grams.
Because of the different processing methods adopted, there are a few different variations clinically for different purposes.
(1). Unprocessed pinellia (Sheng). It is the raw tube, impurities removed, cleaned, dried, and mashed when applied. The form is toxic so that it is mainly used externally for reducing swelling and easing pain;
(2). Purified pinellia (Qing). It is soaked, boiled, or salted in Ku fan (alum) solution, which eliminates the side effects of tingling to throat and reduce the toxicity. This form is mainly used for drying dampness and transforming phlegm. They are close to round or kidney-shaped thick slices, 6 to 18mm in diameter, ivory white skin, yellowish brown rim, looming yellowish white stars scattered in vascular. It is slightly pungent and puckery;
(3). Gingered pinellia (Jiang). It is boiled, salted, or steamed by ginger and alum or fried by ginger only, which is mainly used for transforming phlegm by warming middle-burner and stopping vomiting by descending the reversed Qi. It looks like the purified one, thin slice, glossy surface, transparent, greyish yellow or light yellow, keratin-like texture, and crisp. It is slightly pungent and with ginger flavor;
(4). Pro formula (standard) pinellia (Fa). It is the most commonly used form. It is processed by lime, which is mainly used for cold-phlegm and damp-phlegm while regulating spleen and stomach. It looks like the unprocessed one, yellow or light yellowish white thoroughly, with fine mealiness, crisp quality, slight odor, and thin taste;
(5). Bamboo-juice pinellia (Zhu Li). It refers to unprocessed or pro formula pinellia mixed thoroughly with bamboo juice and then dried in the shade, which thus reduces the warm-dry tremendously. It is suitable for vomiting due to stomach heat, yellow sticky phlegm caused by lung heat, phlegm-heat blocking internally, and aphasia from apoplexy;
(6). Fermented-mass pinellia (Qu). It refers to the herbal leaven processed by flour and ginger juice, which is to stop cough by transforming phlegm, eliminate dyspepsia, and stop diarrhea.
Related Chinese herbal formulas
This herb has been widely used in many herbal remedies for a variety of diseases, among which, the followings are the most famous.
Ban Xia Hou Po Tang (Wan), or Banxia Houpo Tang, from Synopsis of Prescriptions of the Golden Chamber (Jin Gui Yao Lue), is one of the exclusive cures for imagined bolus in throat, which, in the sight of TCM, refers to the status that sputum and saliva obstructing the throat, but actually nothing there but imagined abnormal feeling. Women are prone to this condition, often accompanied with symptoms and signs of lumps in the throat, emotional stagnation, choking sensation in chest, white and greasy coating, and slippery stringy pulse. Now this herbal prescription is frequently used in treatments for pharyngeal neurosis and chronic pharyngitis diagnosed by modern medicine.
Ban Xia Xie Xin Tang (Wan) is designed to lever cold and heat, reduce distension, and dissipate nodules. Main indication is the so-called Pi-syndrome, manifesting feeling fullness and distension in the upper abdomen but no pain, or vomiting, bowel sound, diarrhea, and slightly yellow and greasy coating. Now this herbal formula is often used in treatments for acute and chronic gastroenteritis, chronic colitis, chronic hepatitis, and earlier period cirrhosis, which fall into the scope of deficiency of middle-Jiao and intermingling with cold and heat in TCM.
Ban Xia Bai Zhu Tian Ma Tang is formulated to alternate warm with cool, give both reinforcing and reducing, invigorate spleen and dry dampness, and transform phlegm and dispel wind. Main symptoms are headache and coma due to blocking of the respiratory system, coughing up sticky mucus, dizziness, annoyance, nausea and vomiting, heavy sensation in body, cold extremities, sleep disorders, white greasy coating, and slippery stringy pulse. Now it is mainly used for Menieres disease presenting the above-mentioned symptoms.
Possible side effects and contraindications
As one of toxic Chinese herbs, it may cause poisoning if misused, like taking orally 0.1 to 1.8 grams of unprocessed one, which results in strong stimulation to mouth, throat, and gastrointestinal mucosa. Small dose could lead to tingling in mouth and tongue while large dose to burning pain, swelling, aphonia, salivation, vomiting, numbness in the whole body, spasm, even dyspnea and death caused by paralysis.
TCM wise, pinellia contradicts with aconite. So, it shouldn’t be used in all blood troubles and sufferers of irritating dry cough due to yin deficiency and thirst caused by body fluid impairment.