Corymbia is a genus of flowering gum trees, often called bloodwoods, native to Australia. There are about 113 species of Corymbia, all of which were considered part of the Eucalyptus genus until the 1990s. The three closely related genera — Corymbia, Eucalyptus, and Angophora — collectively form a group called eucalypts.
Gum trees are characterized by the abundant sap that flows from cracks in the trunk. The common name bloodwood is a reference to the dark red color of the sap, also called gum or kino, that flows from wounds on the trunk. The kino is used in folk medicine by the indigenous population of Australia. For example, it is used to make a tea to treat colds, flu, and stomach ailments.
C. aparrerinja, or the ghost gum, grows in arid and sandy climates in central Australia. Its common name refers to the color of its bark, which ranges from white to pale pink. The ghost gum can reach 65 feet (20 meters) n height, and features white, summer blooming flowers. The tree has symbolic associations in the religion of Indigenous Australians and was a frequent subject of the paintings of the Australian artist Albert Namatjira.
C. citriodora, also called blue spotted gum, lemon eucalyptus, and lemon-scented gum, is one of the tallest Corymbia species, reaching a maximum height of 167 feet (51 meters). As its name suggests, the plant has a lemon-like scent. It has a white to tan bark and can flower nearly year-round. C. citriodora is cultivated for its ornamental properties, its timber, its essential oil, and honey production. The oil of the lemon eucalyptus contains citronella, which is used in perfume and as a natural insect repellent.
C. ficifolia, or the red flowering gum, is one of the most popular ornamental species. Native to a small area on the southern coast of the state of Western Australia, the red flowering gum is known for its abundant flowers, which are often red or orange. Some plants feature white or pink flowers, however. C. ficifolia is hardy and grows well throughout temperate climates, but a plant grown from seed can take up to seven years to flower for the first time.
C. calophylla is very similar in appearance to C. ficifolia, and the two species are often difficult to distinguish. C. calophylla, also called marri, Port Gregory gum, or red gum, has larger buds and fruit than other Corymbia species. It is much taller than C. ficifolia in the wild, reaching 160 feet (50 meters), and tends to have lighter colored bark and flowers.