Epimedium longnanense (Berberidaceae), a new species from Gansu, China

Epimedium longnanense, a new species of Epimedium (Berberidaceae) from Longnan Prefecture, Gansu Province, China, is here proposed and illustrated. E. longnanense has large flowers with petals possessing long spur and obvious basal lamina, and thus should be grouped into series Davidianae. The species closely resembles E. flavum of ser. Davidianae in morphology. However, it can be easily distinguished by its elongated rhizome (vs. compact), trifoliolate leaves (vs. five leaflets, sometimes trifoliolate), pale pink or purplish-red inner sepals with 6–8 × 2–3 mm (vs. pale sulphur-yellow, ca. 11 × 4 mm).