We have a very good collection of epimediums in the Asian Collection at the US National Arboretum. It's well labeled and supported by good records. So how did this happen? It seems to have snuck in somehow. Maybe it's a seedling, a cross-pollenated seedling. Anyway it isn't labeled, it isn't mapped, it doesn't match any of our other epimediums living or dead in our records.
It's very attractive and extremely cold resistant. This winter it was the only epimedium not to suffer any winter foliar burn.