Northern rata (
Metrosideros robusta) is a huge forest tree endemic to
New Zealand. It grows up to or taller, and usually begins its life as a
hemiepiphyte high in the branches of a mature forest tree; over centuries the young tree sends descending and girdling roots down and around the trunk of its host, eventually forming a massive, frequently hollow pseudotrunk composed of fused roots. In disturbed ground, or where there are gaps in the forest cover, Northern rata will grow on the ground with a normal but short trunk.