Petrophile sessilis, known as conesticks,[2] is a species of flowering plant in the family Proteaceae and is endemic to New South Wales.

It is an erect shrub with rigid, needle-shaped, divided, sharply-pointed leaves, and oval, spike-like heads of silky-hairy, creamy-yellow flowers.

Petrophile sessilis is an erect shrub that typically grows to a height of 3 m (9.8 ft) and has branchlets and leaves that are silky-hairy when young but become glabrous with age.

The flowers are arranged on the ends of branchlets and in leaf axils in spike-like, oval heads 20–25 mm (0.79–0.98 in) long, with broadly egg-shaped involucral bracts at the base.

[4] Petrophile sessilis was first formally described in 1827 by Josef August Schultes in the 16th edition of Systema Vegetabilium from an unpublished description by Franz Sieber.