Objective: Commercial samples of Ziwan have been investigated and identified to find out the original species in circulation.
Method: Comparative histological and morphological identification.
Result: The main original plant species are Aster tataricus, Ligularia fischeri, L. hodgsonii, L. intermedia, L. wilsoniana, L. sibirica var. araneosa, L. veitchiana and L. caloxantha.
Conclusion: The root and rhizome of A. tataricus are used as Ziwan in most areas of China; but those of Ligularia species are used as Ziwan(named Shanziwan) in southwest, and part of northwest and northeast areas of China.