Smooth-barked apple

Angophora costata is a tree that typically grows to a height of 30 m (100 ft) and forms a lignotuber. It has smooth pinkish or orange-brown bark that weathers to grey and is shed in small scales. Young plants and coppice regrowth have sessile, elliptical to egg-shaped leaves arranged in opposite pairs with a stem-clasping base, 60–125 mm (2.5–5 in) long and 20–65 mm (0.8–2.6 in) wide. Adult leaves are arranged in opposite pairs, glossy green but paler on the lower surface, lance-shaped or curved, 70–190 mm (2.8–7.5 in) long and 12–35 mm (0.5–1.4 in) wide on a petiole 9–25 mm (0.4–1.0 in) long. New leaf growth is strongly tinted with red. The flower buds are arranged on the ends of branchlets on a branched peduncle 3–25 mm (0.1–1.0 in) long, each branch of the peduncle with usually three buds on pedicels 3–15 mm (0.1–0.6 in) long. Mature buds are oval to globe-shaped, up to 10 mm (0.4 in) long and 11 mm (0.4 in) wide. There are five sepals up to 3 mm (0.1 in) long and the petals are white to creamy white with a green keel, 3–5 mm (0.1–0.2 in) long and 3–6 mm (0.1–0.2 in) wide. Flowering occurs from October to December. The fruit is an oval or bell-shaped capsule up to 20 mm (0.8 in) long and wide. New seedlings have petiolate round cotyledon leaves 1.5 cm wide and long.

Angophora costata grows in sandy soil, often over sandstone and occurs naturally in Queensland and New South Wales. It is widely distributed in south-eastern Queensland and disjunctly in the White Mountains National Park. In New South Wales it mainly occurs in coastal areas south from Coffs Harbour to Narooma and as far west as the Blue Mountains. It is found from sea level to an altitude of 300 m (1,000 ft) in areas of predominantly summer rainfall receiving 600 to 1,200 mm (25 to 45 in) a year. Maximum temperatures across its range vary from 25 to 35 °C (77 to 95 °F) and minimum temperatures from 0 to 8 °C (32 to 46 °F), with anywhere from 0 to 50 days of frost. In Victoria it is a commonly planted ornamental and is naturalised in some places. It grows in open forest and woodland, in association with such species as Sydney peppermint (Eucalyptus piperita), bangalay (E. botryoides), grey gum (E. punctata), blue-leaved stringybark (E. agglomerata), white mahogany (E. acmenoides), broad-leaved white mahogany (E. umbra), large-fruited red mahogany (E. scias), red bloodwood (Corymbia gummifera), yellow bloodwood (C. eximia), pink bloodwood (C. intermedia) lemon-scented gum (C. …

Angophora costata trees can live over 100 years. The species responds to bushfire by resprouting from epicormic buds and its lignotuber; shoots on branches of older specimens arise after a month, while shoots resprout from the trunk and base of young plants within a month of a hot fire. Seedlings appear within 9 to 10 months. The tree is parasitised by the long-flowered mistletoe (Dendrophthoe vitellina). The flowers are eaten by the grey-headed flying fox (Pteropus poliocephalus) and little red flying fox (P. scapulatus), while the seed is eaten by the crimson rosella (Platycercus elegans). Although the bark of A. costata is smooth, many invertebrates are found there. Several spiders in the family Salticidae, including Servaea vestita, and pseudoscorpions live under loose bark. The flattened bug Stenocotis depressa evades detection by camouflage, and cockroaches and huntsman spiders live under the loose bark at the base of the trunk. Angophora costata is also susceptible to the fungal pathogens Quambalaria pitotheka, Aulographina eucalypti and Cryptococcus neoformans.

Smooth-barked apple grows well in a variety of situations and can be easily grown from seed in a loose, well-drained seed-raising mixture. Some specimens have a straight trunk while others have a more branching habit with twisted trunks. The tree sometimes sheds branches and should not be planted close to buildings.