A taxonomic revision of unifoliolate Chinese Epimedium L. (Berberidaceae)

Five Chinese species of Epimedium (Berberidaceae), E. simplicifolium T. S. Ying, E. baojingensis Q. L. Chen & B. M. Yang, E. zhushanense K. F. Wu & S. X. Qian, E. glandulosopilosum H. R. Liang and E. elachyphyllum Stearn are the only species of the genus previously described with unifoliolate leaves. Here, the authors review these five species based on extensive examination of specimens in herbaria and careful observation in the field and garden. E. simplicifolium is treated as a synonym of E. acuminatum Franch., and with the exception of E. elachyphyllum, the taxa are found to have predominantly trifoliolate and only occasionally unifoliolate leaves. Neotypes for E. zhushanense and E. glandulosopilosum are designated. In addition, we describe some characters of E. baojingensis, E. zhushanense, E. glandulosopilosum and E. elachyphyllum.