Root of Tatarian Aster Classic Formulas … Natural Herb Library

Primary Actions

Moistens the Lung and transforms phlegm while stopping cough ... raw Zi Wan is a core cough-lane root for chronic, lingering, or difficult-to-resolve respiratory patterns.
Directs rebellious Lung Qi downward ... it is used when coughing comes with wheezing, stubborn sputum, or difficulty getting the Lung to descend smoothly.
Keeps some moistening even while expelling phlegm ... this lets Zi Wan bridge dry-irritative cough and cough with sticky difficult sputum.

Zhi Sou San ... classic lingering-cough formula in which Zi Wan is one of the core antitussive roots.
Bai Bu Tang and similar cough prescriptions ... Zi Wan commonly pairs with Bai Bu for stubborn cough with weak Lung descent.
Mixed phlegm-dryness formulas with Bai Qian, Kuan Dong Hua, or Jie Geng ... common logic when downward movement and expectoration are both needed.

Traditional materia medica places Zi Wan among the key roots that moisten the Lung, transform phlegm, and direct Qi downward.
The raw and prepared forms overlap, but processing changes texture and handling enough that the two pages should not collapse into one.