Metrosideros

Metrosideros is a genus of evergreen trees and shrubs in the myrtle family (Myrtaceae) native to the Pacific region. The genus comprises about 50 species, including Metrosideros excelsa (pōhutukawa) from New Zealand and Metrosideros polymorpha (ōʻihia lehua) from Hawaii, as well as numerous rata species in New Zealand. Metrosideros is best known for its showy inflorescences: dense clusters of flowers made up of thousands of conspicuous stamens, often in bright red, orange, or yellow, which attract a variety of pollinators.

Leaves are typically small and leathery, and the plant forms range from compact shrubs to large forest trees. The fruit is a woody capsule containing seeds. These trees are generally adapted to a range of soils, including poor and volcanic soils, and many species are able to colonize disturbed sites.

Distribution and ecology: Metrosideros species occur across the Pacific, with significant populations in New Zealand, Hawaii, Tahiti, and nearby islands. They occupy diverse habitats from coastal forests to montane woodlands and, in some locations, volcanic landscapes. Their bright flowers provide nectar for birds, bees, and other pollinators, and they often play important roles in local forest structure as canopy or subcanopy trees.

Conservation and uses: Several Metrosideros species are of conservation concern due to habitat loss, invasive species, and disease. In Hawaii, rapid ohia death caused by Ceratocystis fungi threatens M. polymorpha populations and forest integrity. In New Zealand, some rata species face habitat pressures, though many remain widespread. Aside from ecological and cultural value, Metrosideros species are used ornamentally and, in some regions, for timber and traditional purposes.