Qing Ban Xia (清半夏; Qīng Bàn Xià; Latin: Pinelliae Rhizoma; English: alum-processed pinellia rhizome) is the dried tuber of the pinellia plant, a low perennial of the arum family, processed with alum until its irritant toxicity is lowered — the translucent, grayish-white pieces with a slightly rough feel that practitioners add to formulas when sticky phlegm and a thick tongue coat keep the chest heavy. It is warm, acrid with a bitter note, enters the Spleen, Stomach, and Lung channels, and its core actions are to dry damp and resolve phlegm, and to lower the rebellious qi and stop vomiting. The usual amount is 3–9 g in a decoction, with far smaller amounts in home teas. Soak the pieces 30 minutes and cook 20 minutes — no special first, last, or wrapped step. It is a medicinal piece — the raw form is never used at home.
It is not Jiang Ban Xia. The ginger-processed pinellia is also warm, acrid, and slightly bitter — it lower the rebellious qi and stop vomiting, better for nausea and vomiting from a cold-damp stomach; this alum-processed piece is acrid-bitter and drying — it dries damp and resolves phlegm, better for sticky, hard-to-clear phlegm with a thick tongue coat. It is not a general phlegm or stomach herb; it acts within clear patterns. In yin-deficiency dry heat — dry mouth, scanty phlegm — or in stomach-fire vomiting — yellow vomit, bitter mouth — using it on your own is a poor match. Chronic cough with blood-streaked phlegm, or a child who is markedly unwell, needs a clinic first. Do not take it yourself for a long time.
It is used most often for three patterns:
- Damp-phlegm blockage — cough with much sticky phlegm, a heavy chest, poor appetite, a thick greasy tongue coat
- Rebellious stomach qi — nausea and vomiting, especially after rich or cold food, a full chest, frequent belching
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Yin-deficiency dry heat, stomach-fire vomiting, pregnancy, or nursing — seek care / skip it
Warm, acrid, and drying, it is not a daily "phlegm-clearing tea" to keep drinking. Drying when there is no damp-phlegm, or in a yin-deficient body, burns the fluids instead of helping.
When dampness from the plum-rain season or from rich food gathers into phlegm — the chest feels heavy, cough brings up much sticky phlegm, the tongue coat turns thick and greasy — the body needs a dry-and-settle rather than a strong purge. Qing Ban Xia is warm, acrid, and bitter. It dries the damp, resolves the phlegm, and lowers the rebellious stomach qi, which is why it appears in Er Chen Tang (Two Aged Decoction)–type formulas. It settles more than it pushes. In yin-deficiency dry heat, or without damp and phlegm, more makes it worse.
Qing Ban Xia is not a catch-all phlegm or stomach herb. In yin-deficiency dry heat, in stomach-fire vomiting, in pregnancy, or without damp and phlegm, using it alone is a poor match. Whether it belongs in a formula, and at what dose, should be decided by a licensed Chinese medicine practitioner after pattern diagnosis.
