Xanthosia peduncularis is a spreading perennial herb in the family Apiaceae and is endemic to the south of Western Australia. It has trifoliate leaves at the base of the plant and cream-coloured flowers in a compound umbel with 3 or 4 rays.
Xanthosia peduncularis is a spreading perennial herb that typically grows to a height of about . Its leaves are trifoliate, arranged at the base of the plant, the leaflets linear or wedge-shaped. The flowers are arranged in a compound umbel with the flowers arranged in 3 or 4 rays and a few central flowers. There are narrow involucral bracts that are longer than the flowers and the sepals are heart-shaped. Flowering occurs from September to November.[1]
Xanthosia peduncularis was first formally described in 1867 by George Bentham in his Flora Australiensis from specimens collected by James Drummond.[2] The specific epithet (peduncularis) means "pedunculate".[3]
This species of xanthosia grows in gravelly sand in the Esperance Plains bioregion of southern Western Australia.
Xanthosia peduncularis is listed as "Priority Three" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions, meaning that it is poorly known and known from only a few locations but is not under imminent threat.[4]