(Ailanthus altissima), rapid-growing tree, in the family Simaroubaceae, native to China but widely naturalized elsewhere. It has been planted as a yard and street tree in urban centres, because of its resistance to pollution, freedom from insects and disease, and ability to grow in almost any soil.

The tree of heaven grows to 18 metres (60 feet) or more, producing long, many-parted leaves, which emit a rank odour when bruised. Male trees bear unpleasantly scented flowers. Female trees produce winged fruits, tannish orange when ripe. Several varieties are known, among them A. altissima sutchuenensis, with purplish leaf stalks and whitish underleaf, and A. altissima erythrocarpa, with brilliant red seed clusters.