Angophora costata, commonly known as Sydney red gum, rusty gum or smooth-barked apple, is a species of tree that is endemic to eastern Australia. Reaching 30 m (100 ft) in height, the species has distinctive smooth bark that is pinkish or orange-brown when new and fades to grey with age. Its lance-shaped leaves are arranged in opposite pairs along the stems, with white or creamy white flowers appearing from October to December. The flower buds are usually arranged in groups of three, followed by ribbed, oval or bell-shaped fruit.