Chrysophanic \Chrys`o*phan"ic\, a. Pertaining to, or derived from, or resembling, chrysophane. {Chrysophanic acid} (Chem.), a yellow crystalline substance extracted from rhubarb, yellow dock, sienna, chrysarobin, etc., and shown to be a derivative of an anthracene. It is used in the treatment of skin diseases; -- called also {rhein}, {rheic acid}, {rhubarbarin}, etc.