Hybridization among Epimedium (Berberidaceae) species native to China

► Self-pollinations of nine populations indicated high incompatibility (at most 6.76%, usually 0% in capsule-set). ► Interspecific cross-pollinations showed high crossabilities in any cross combination (15.38-92.44% in capsule-set), and the F1 seeds obtained high germination rates (>20%). ► The F1 hybrids of three interspecific cross combinations were raised to mature. The morphology, karyomorphology of somatic cell, and meiosis of PMCs of these F1 plants were studied. ► A series of experimental crosses provided strong evidence for an outbreeding system and weak internal barrier to hybridizations in the taxa studied.