A distinctive, previously undescribed species of Epimedium (Berberidaceae), which we propose naming E. tianmenshanensis, was found during a floristic survey in Hunan, China. It is similar to E. baojingense and E. franchetii, but has smaller flowers and petals with a short, blunt spur. We determined the phylogenetic position of the new species using DNA sequences of nuclear ITS and two chloroplast regions (atpB-rbcL intergenic spacer and matK). Molecular evidence indicates that E. tianmenshanensis occupies a distinct group related to E. baojingense.