Abstract: The karyotypes of twelve barrenwort species were studied by means of the cytological observation of root-tips. The results show that their karyotypes are similar to each other , with one pairs of middle satellite chromosomes and symmetric karyotype . Among them, the karyotype formulas of Epimedium sagittatum, E. myrianthum, E. acuminatum , E. wushanense, E. simplicifloum, E. yinjiangense, E. luodianense, E. davidi , E. pubigerum , E. franchetii and E. alpinum are 2n = 2x = 6m (2SAT ) + 6sm, and E. leptorrhizum 2n = 2x= 8m (2SAT ) + 4sm . Results of karyotypes analysis supported the opinion of the barrenwort is very conservative in evolution , Our karyotype study suggested that genus Epinedium should be the oldest group in the family of Berberidaceae .

Key words: Epimedium