Macaranga is a large genus of Old World tropical trees in the family Euphorbiaceae, placed in the subtribe Macaranginae within tribe Acalypheae and the order Malpighiales. The genus comprises over 300 species distributed across tropical Africa, Asia, Australasia, and the islands of the Indian and Pacific Oceans. It was first formally described in 1806, based on specimens collected on the island of Mauritius.
Many species are recognised by their strikingly large, often peltate leaves — a trait particularly conspicuous in Macaranga gigantea. As a group, Macarangas are classic pioneer trees, colonising disturbed and secondary forest with rapid growth. Several species have evolved a notable mutualistic relationship with ants of the genus Crematogaster (subgenus Decacrema): the trees provide hollow stems as nesting chambers and sometimes secrete food-body nectar, while the ants defend the host against herbivorous insects. This ant-plant symbiosis has made Macaranga a model system in tropical ecology research.
The genus is also notable economically and culturally in parts of its range. Macaranga indica yields Macaranga gum, a crimson resin with traditional uses. In Sabah, Malaysia, the leaves of Macaranga tanarius are used by the Rungus people to wrap cooked rice, both preserving it and imparting a characteristic aroma. The foliage of various species also serves as a larval food plant for certain moths, including Endoclita malabaricus.
Distribution
Macaranga is native to tropical Africa, Asia, Australasia, and numerous islands of the Indian and Pacific Oceans, with the centre of diversity in Southeast Asia and the Indo-Pacific region. The genus spans lowland rainforests to montane edges across this broad Old World range.
Ecology
Many Macaranga species are pioneer trees that rapidly colonise disturbed habitats and secondary forest. A particularly well-studied ecological trait is the mutualistic symbiosis with Crematogaster ants (subgenus Decacrema): hollow stems provide nesting sites and the trees may supply food bodies or nectar, while the ants repel or consume herbivorous insects attacking the host. This system has been the subject of extensive ecological research on coevolution and plant defence.
Cultural Uses
Macaranga indica produces a crimson resin known as Macaranga gum that has traditional applications. The leaves of Macaranga tanarius are used by the Rungus indigenous people of Sabah, Malaysia, to bundle and preserve cooked rice, also imparting a pleasant aroma to the food.
