Isopogon trilobus, commonly known as barrel coneflower,[2] is a species of flowering plant in the family Proteaceae and is endemic to South Coast Western Australia.

It is a shrub with wedge-shaped leaves with lobed or toothed margins, and oval, spherical or barrel-shaped heads of cream-coloured to yellow flowers.

The flowers are arranged on the ends of branchlets in sessile, oval, spherical or barrel-shaped heads 25–30 mm (0.98–1.18 in) wide with hairy, broadly egg-shaped involucral bracts at the base.

[6][7] Isopogon tripartitus R.Br., that Brown described in 1830 in the Supplementum to his Prodromus Florae Novae Hollandiae et Insulae Van Diemen,[8][9] is now considered a synonym of the older name.

[11] Barrel coneflower is widespread from the Stirling Range east to Israelite Bay along the south coast of Western Australia where it grows on sandplains, dunes or rocky outcrops, on sandy soils, sometimes over laterite, in heathland or shrubland communities.