Styphelia williamsiorum is a species of flowering plant in the heath family Ericaceae and is endemic to a small area in the south-west of Western Australia. It is a low, compact shrub with decussate, narrowly egg-shaped leaves, and deep purple, tube-shaped flowers with hairy lobes.
Styphelia williamsiorum is a low, compact shrub that typically grows up to high and side, its young branchlets hairy. The leaves are decussate, pressed against the stems, narrowly egg-shaped, long and wide. The flowers are arranged singly in leaf axils with elliptic to egg-shaped bracts long and bracteoles long at the base. The sepals are narrowly egg-shaped, long. The petals are deep purple, joined at the base, forming a tube long with the lobes curved back, long and densely hairy on the inside. Flowering occurs between mid-October and mid-December and the fruit is narrowly elliptic, long and long.[1]
Styphelia williamsiorum was first formally described in 2017 by Michael Clyde Hislop and Caroline Puente-Lelièvre in the journal Nuytsia.[2] The specific epithet (williamsiorum) honours Don and Joy Williams of Badgingarra.
This species occurs in the Geraldton Sandplains bioregion of south-western Western Australia from south of Eneabba to Badgingarra and as far east as the Alexander Morrison National Park, where it grows in shallow sandy soil in low heath.
Styphelia williamsiorum 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.[3]