Lasiopetalum pterocarpum E.M. Benn. & K.A. Sheph. sp. nov. is described and illustrated. The distinct winged fruit, for which L. pterocarpum is named, is unique within Lasiopetaleae. Lasiopetalum pterocarpum is allied to L. floribundum, which shares a similar habit, large ovate leaves and loose dichasial inflorescences. It can be readily distinguished from L. floribundum by its discolorous and strongly-lobed leaves, the absence of glandular hairs on the peduncles, and its larger seeds. This species is known from only one population south of Perth and is classified as critically endangered.