The phenotypic variations of 17 populations of Catalpa fargesii f. duclouxii, theirs 7 phenotypic traits including fl owers branch length, upper calyx length, lower calyx length, corolla and fl ower diameter were investigated. The results show that there existed notable variations of phenotypic characters of f lowers within and among the groups, the differences of the 7 phenotypic traits reached an extremely signif icant level(P < 0.01), the mean variation coeffi cient was 25.94%, the amplitude of variation...