[1] They are large trees, often rising above the rainforest canopy.

The leaves are evergreen, alternate, simple, elliptical, up to 15 cm long, with a serrate to serrulate margin.

Vernation lines parallel to the midvein are often visible - a very unusual characteristic.

The fruit is 6–15 cm long, and roughly conical.

A central plug drops out at maturity, releasing the winged seeds to be dispersed by wind.