Shrubs or more rarely trees, with smooth and shedding, fibrous or papery layered bark; young stems silky, glabrescent, with or without stem flanges or grooves near the base of leaves. Leaves alternate. Flowers actinomorphic, bisexual or rarely male only, axillary on condensed leafy shoots where solitary, or in clusters of 2-several. Petals 5, broadly obovate, deciduous; sepals 5, persisting or falling from the fruit; stamens c. 10–45, shorter than the petals, anthers with a gland near the connective, versatile, opening by slits. Fruit a loculicidal capsule (shed before next flowering or long persisting), in some species lobed in cross-section, valves opening at the apex; seeds ovate, with reticulate surface pattern and with or without loose cells or wings along the margins, or linear and with a linear-striate surface pattern.
85 species currently recognized, 4 extending through Malesia from southern Myanmar to New Guinea; 82 species (all but 2 endemic) in Australia.
The common name of Teatree derives from the practice of brewing the leaves of some species for tea.