Feng Huang Yi

Feng Huang Yi (凤凰衣) is most commonly recorded in Chinese materia medica not as a plant at all but as the thin inner membrane of the hen's eggshell (the chorioallantoic membrane peeled from the inside of a chicken egg after the contents are removed), used as a folk remedy for chronic cough and to promote healing of ulcerations. Some regional sources apply the same name to flower-bract structures of certain ornamental plants, but without a corroborating Latin name the identification cannot be made with confidence. Because the substance is most likely an animal-derived material rather than a plant — and possibly not in standard pharmacopoeial use — the record follows the unidentifiable/non-plant null-pattern.