Metrosideros robusta forms a evergreen large tree, up to 80 ft (24 m) tall. The dark green leaves are oval in shape, and 1–1.6 in (2.5–4 cm) long. The flowers are dull red, summer.
Metrosideros robusta is found in the forests of the North Island, Three Knights Island, and the western South Island, New Zealand. This plant often begins life as an epiphyte, perching in another tree. In time roots are sent down to the ground, and the metrosideros takes over. In New Zealand it is commonly called by its Maori name, rata.