Toona australis is a large deciduous tree with a spreading crown, commonly attaining a height of 20-30 m and a girth of 1.8-3 m. Bark dark grey or reddish-brown, smooth up to middle age, afterwards rough, with shallow reticulate cracks exfoliating in irregular woody scales. Blaze 1.3-1.5 m, fibrous throughout, pink or pinkish-brown, sometimes with just a few white bands towards the outside, turning brown on exposure, bitter to the taste, juice turning purple on the blade of a knife. Leaves 30-50 cm long, on young trees up to 90 cm long, usually imparipinnate, sometimes paripinnate by the abortion of the terminal leaflet; leaflets 11-29, opposite or alternate, 5-15 x 2-6 cm, lanceolate or ovate-lanceolate, acuminate, glabrous, pubescent, margin entire or wavy, base oblique; petiolules 0.3-1.3 cm long. Flowers small, honey scented, cream coloured, in drooping or sub-erect terminal panicles, usually shorter than the leaves. Calyx divided nearly to the base. Petals 5 mm long, ovate-oblong, sub-acute, with ciliate margins. Capsule dark brown, 1.8-2.5 x 0.5-0.8 cm, oblong, usually smooth outside, sometimes sparsely lenticellate. Seeds pale brown, very light, winged at both ends, 1.3-1.5 cm long including the wing. The synonymous name ‘cedrela’ is from the Latin ‘cedrus’, the cedar, the name given on account of its scented wood.