Corymbia calophylla, commonly known as marri, is a species of flowering plant in the family Myrtaceae and is endemic to the southwest of Western Australia. It is a tree or mallee with rough bark on part or all of the trunk, lance-shaped adult leaves, branched clusters of cup-shaped or pear-shaped flower buds, each branch with three or seven buds, white to pink flowers, and relatively large oval to urn-shaped fruit, colloquially known as honky nuts. Marri wood has had many uses, both for Aboriginal people, and in the construction industry. Description Corymbia calophylla is a large tree, or a mallee in poor soil, and that typically grows to a height of , but can reach over . The largest known individual C. calophylla is tall, has a girth and a wood volume of . The trunk of the tree may become up to wide, the branches becoming large, thick and rambling. It has rough, tessellated, grey-brown to red-brown bark that extends over the length of the trunk and branches. Adult leaves are arranged alternately, thick and the same shade of glossy green on both sides, broadly lance-shaped to egg-shaped and tapered or rounded at the base. The leaf blade is long and wide with a narrowly flattened or channelled petiole long. It blooms between December and May, producing white to pink flowers. The flower buds are arranged on the ends of branchlets on a branched peduncle that is circular or angled in cross-section. Each branch of the peduncle has buds in groups of three or seven on pedicels long. Mature buds are club-shaped or pear-shaped, long and wide with a flattened operculum. The fruits or gumnuts form later and can remain on the tree for a year or more. They are oval to urn-shaped, long and wide on a pedicel long. The large nuts produced carry large seeds which are an important food source for native bird species such as cockatoos. The tree propagates readily from seeds. It is distinctive among bloodwoods for its very large buds and fruit, colloquially known as honky (or honkey) nuts, in Western Australia. Taxonomy and naming The name Eucalyptus calophylla was first published in 1831 by Robert Brown in Journal of the Royal Geographical Society of London, but without a description it was deemed to be a nomen nudum. Brown used a specimen grown at Kew to include the species in the family as