Petrophile merrallii is a species of flowering plant in the family Proteaceae and is endemic to southwestern Western Australia. It is an erect shrub with spreading, needle-shaped leaves and oval to spherical heads of hairy yellow flowers.
Petrophile merrallii is an shrub that typically grows to a height of and has hairy young branchlets and leaves that become glabrous with age. The leaves are spreading needle-shaped, long and rough to the touch. The flowers are arranged on the ends of branchlets in sessile, oval to spherical heads up to about in diameter, with many overlapping egg-shaped involucral bracts at the base. The flowers are about long, yellow and hairy. Flowering occurs from August to October and the fruit is a nut, fused with others in an oval to spherical head up to in diameter.[1]
Petrophile merrallii was first formally described in 1995 by Donald Bruce Foreman in Flora of Australia from material collected near Southern Cross in 1968.[2] The specific epithet (merrallii) honours Edwin Merrall, a miner who collected plant specimens in Victoria 1887–1888.[3]
This petrophile grows in heath and mallee on sandy-gravelly soils over laterite between Southern Cross, Muntadgin, Pingrup and Lake Grace in the Avon Wheatbelt, Coolgardie and Mallee biogeographic regions of southwestern Western Australia.
Petrophile merrallii is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.