Hibbertia aplacophylla K.R.Thiele sp. nov. is here segregated from H. notibractea J.R.Wheeler. It comprises plants from a disjunct population on the far south coast of Western Australia that differ most significantly from H. notibractea in having leaves with a distinct midrib and recurved margins (cf. flat with neither midrib nor recurved margins), sepals that are quite glabrous (cf. ciliate-margined), and anthers held erect at the ends of the fused filaments (cf. deflexed).