Cardamine tangutorum O.E.Schulz (Brassicaceae), a new synonym of Cardamine macrophylla Willd

<i>Cardaminemacrophylla</i> Willd. and <i>Cardaminetangutorum</i> O.E.Schulz are both widely distributed plants of the genus <i>Cardamine</i> L. in East Asia, and they are regarded as the same species in <i>Flora of China</i>. In this study, through literature and specimen research, morphological measurement and phylogenetic analyses, the results show that the traditional distinguishing characters cannot distinguish the two species. <i>Cardaminetangutorum</i> O.E.Schulz inserted into the branch of <i>Cardaminemacrophylla</i> Willd. in the molecular phylogenetic tree. Therefore, based on the results of this study, <i>Cardaminetangutorum</i> O.E.Schulz was treated as the synonym of <i>Cardaminemacrophylla</i> Willd.