Abstract: Aims In order to understand the geographical distribution of threatened species of genus Epimedium in China, and to provide the basis for resource conservation and utilization. Methods The data of Chinese Virtual Herbarium (CVH), China National Specimen Information Infrastructure (NSII), the Royal Botanic Garden Edinburgh (E), Royal Botanic Gardens, Kew (K), Muséum National d'Histoire Naturelle (P) and Universitat Wien (WU) were used. And the specimens of Herbarium of Institute of Medicinal Botany, Chinese Academy of Medical Sciences (IMD), which is not included in the sharing platform but abundant in Epimedium specimens, were also examined. At the same time, combined with our field investigations and literature review, the specimen information of 25 species and 1 variety of Epimedium in China were systematically collected to verify the specimen identification and geographical distribution, and updated the endangered categories and criteria. Important findings A total of 1017 specimens of 428 numbers were examined, and only 666 specimens of 274 numbers (64.02%) were correctly identified. Nineteen taxa (73.08%) had found new distribution compared with the recorded of Flora of China. However, six species were currently known to be distributed only in the type locality. The three provinces with the highest abundance of threatened species were Sichuan (12 species), Hubei (7 species) and Guizhou (6 species and 1 variety). The endangered categories or criteria of 22 taxa were suggested to be adjusted. Epimedium enshiense B. L. Guo et Hsiao, E. reticulatum C. Y. Wu, E. fangii Stearn and E. elachyphyllum Stearn were suggested to be upgraded to Critically Endangered (CR). The endangered categories of E. flavum Stearn, E. glandulosopilosum H. R. Liang, E. mikinorii Stearn, E. sagittatum var. glabratum Ying, E. truncatum H. R. Liang and E. zhushanense K. F. Wu et S. X. Qian were suggested to be upgraded to Endangered (EN). Epimedium simplicifolium Ying and E. fargesii Franch. were respectively suggested to be downgraded from Critically Endangered (CR) and Endangered (EN) to Vulnerable (VU). For another 10 species, the endangered categories remained unchanged and only the criteria were adjusted. The main reasons for the endangered plants of Epimedium were narrow distribution, habitat decline and population decrease. Errors in the identification of specimens of threatened species of Epimedium were prominent. Most species of this genus were distributed in narrow areas and were highly threatened. Therefore, the protection of species diversity should be paid more attention. The?evaluation of endangered categories and criteria is a dynamic process that requires long-term monitoring and constant updating.

Key words: Epimedium, threatened species, herbarium specimens, geographical distribution, endangered categories and criteria, species conservation