Backhousia subargentea (syn. Choricarpia subargentea) is a rare Australian rainforest tree, growing near Mullumbimby in north eastern New South Wales and from Boonah to Imbil in south eastern Queensland. Common names include giant ironwood, ironwood box, scrub ironwood and lancewood. The New South Wales habitat of Backhousia subargentea is dry rainforest thickets on hillsides near Mullumbimby. It grows in association with the shatterwood and wild quince.