Taxonomy of Epimedium (Berberidaceae) with special reference to Chinese species

Epimedii Herba is a commonly used traditional Chinese herbal medicine. Five Epimedium species are included in Chinese Pharmacopoeia and most species of Epimedium are used as Epimedii Herba in practical application. However, as the largest herbaceous genus of the Berberidaceae, Epimedium has many taxonomic controversies which hinder the effective use of Epimedii Herba. This paper reviewed the taxonomic research related to Epimedium, including taxonomic history, taxonomic values of morphological characters, species and distribution, infra-genera taxonomic system and the taxonomic research of Chinese Epimedium. For instance, we recognized Epimedium wushanense and clarified that the species, as described in Flora Reipublicae Popularis Sinicae and Flora of China, actually includes four Epimedium species similar in leaflet shape. In general, it was recognized here that Epimedium comprises 62 species, of which 52 species are distributed in China. For Chinese Epimedium species with the most taxonomic problems, the taxonomic research on the taxa was reviewed and the newest species key was proposed along with proposals for those taxonomic problems needing further resolution. This review is of great implication for the identification, exploration and utilization of Epimedii Herba.