Two new Western Australian species related to Hibbertia priceana (Dilleniaceae)

Abstract

Hibbertia priceana is a rare species found in two localised areas in southern south-western Western Australia, near Ongerup and in the vicinity of Wickepin and Harrismith. Two new species that are morphologically similar to H. priceana but are disjunct and distinct from it are described in this paper. Hibbertia hapalophylla is a new, potentially geographically restricted and rare species first collected during botanical surveys for a mining project near Mount Holland in the Western Australian Goldfields. It was initially collected from, and only known from, disturbed areas on an active mine site, but larger populations were subsequently discovered on a nearby sandplain, from where is was likely introduced to the mine site on sand transported for construction purposes. The second new species, Hibbertia remanens, appears to be restricted to small areas of remnant vegetation near Cunderdin and Kellerberrin in the Western Australian wheatbelt. The three species differ mainly in their leaf shapes in section, with H. priceana having flat leaves with the abaxial lamina fully exposed, H. remanens having recurved leaf margins with the abaxial shallowly grooved either side of the midrib, and H. hapalophylla having strongly revolute margins with the abaxial lamina surface concealed within lacunae formed between the margins and midrib.