This paper is proposed to describe three new species and four varieties from Cheju Island to central part of Korea in Southern Korea. The new plant taxa are as follows: Clematis taeguensis Y. Lee, sp. nov.; Prunus linearipetalus Y. Lee, sp. nov.; Vicia linearifolia Y. Lee, sp. nov.; Clematis brachyura Maxim, var. hexasepala Y. Lee, var. nov.; Ranunculus quelpaertensis(Lev.) Nakai var. albiflorus Y. Lee, var. nov.; Aconitum napiforme Lev. et Vaniot var. albiflorum Y. Lee, var. nov.; Ajuga decumbens Thunb. var. rosa Y. Lee, var. nov.