Two new species of Hibbertia (Dilleniaceae) from near Ravensthorpe in Western Australia

Abstract

Two new and geographically restricted species allied to Hibbertia hamulosa J.R.Wheeler and H. mucronata (Turcz.) Benth. are newly described. Hibbertia abyssa Wege & K.R.Thiele is distinctive for its long, slender and more or less glabrous peduncles, and sepals with both uncinate and minute stellate hairs on the outer surface. This species, which occurs on shallow soils with siltstone outcropping, is known from a single population adjacent to the nickel mine on Bandalup Hill and has recently been nominated for listing as Declared Rare Flora. Hibbertia atrichosepala Wege & K.R.Thiele is readily distinguished from allied species by its completely glabrous sepals. It is a narrow-range endemic of rocky, lateritic habitats in the Ravensthorpe Range and is listed as having Priority One conservation status.