Diplolaena ferruginea is a species of flowering plant in the family Rutaceae and is endemic to Western Australia. It has leaves arranged opposite and red and green pendulous flowers.
Diplolaena ferruginea is a small, spreading shrub to high with smooth branches covered in scales or star-shaped hairs. The leaves are simple, leathery, upper surface bright green, arranged opposite, long, wide, flat, smooth, covered in star-shaped hairs or scales. The red or green corolla has 5 overlapping, linear, rust-coloured petals long, outer bracts long, densely covered in rust-colored short matted hairs, pedicels long and numerous, smooth, stamens long, smooth and hairy. Flowering occurs from July to October.
Diplolaena ferruginea was first formally described in 1971 by Paul Graham Wilson and the description was published in Nuytsia. The specific epithet (ferruginea) means "rust-colored".
This species grows in a variety of situations including gravel, sand, clay on or near the Western Australian coast.