This paper is proposed to describe three new species, two varieties and one forma of flowering plants from central Korea and the Island of Cheju in southern Korea. The taxa of new plants are as follows; Astragalus koraiensis Y. Lee, sp. nov.; Astragalus nakaianus Y. Lee, sp. nov.; Commelina minor Y. Lee & Oh Y., sp. nov.; Cirsium rhinoceros Nakai var. albiflorum Y. Lee, var. nov.; Tripterospermum japonicum (Sieb. & Zucc.) Max. var. albiflorum Y. Lee, var. nov.; Adenophora remotiflora (Sieb. & Zucc.) Miq. form. albiflora Y. Lee, form. nov.