Jarrah forest is tall open forest in which the dominant overstory tree is Eucalyptus marginata (jarrah). The ecosystem occurs only in the Southwest Botanical Province of Western Australia. It is most common in the biogeographic region named in consequence Jarrah Forest. Most jarrah forest contains at least one other co-dominant overstory tree; association with Corymbia calophylla is especially common, and results in which is sometimes referred to as jarrah-marri forest.