ohia

Ōhiʻa, or ʻōhiʻa lehua, is Metrosideros polymorpha, a large evergreen tree in the myrtle family native to the Hawaiian Islands. It is among the most widespread and ecologically important trees in Hawaii, occupying habitats from dry forests to wet montane forests. The tree typically reaches 10–20 meters, with some individuals exceeding 30 meters, and forms a broad canopy. Leaves are leathery, dark green, and about 5–12 cm long. The inflorescences bear brush-like clusters of small flowers, usually bright red, orange, or rarely yellow, which attract pollinators and are visible throughout much of the year.

Ōhiʻa is a foundational species in Hawaiian ecosystems. It commonly colonizes new lava flows and contributes to watershed protection and soil formation. It supports a diverse understory and provides habitat for many native invertebrates and birds, including honeycreepers, while also supporting overall forest structure.

In recent decades a fungal disease known as Rapid Ohia Death (ROD) has killed extensive stands of ʻōhiʻa across the islands. Two pathogens, Ceratocystis lukuohia and Ceratocystis huliohia, cause rapid decline and mortality; transmission is linked to wounds and root grafts, and the exact spread pathways are still studied. There is no widely available cure; management emphasizes early detection, restrictions on movement of potentially infected material, sanitation, and restoration using resistant individuals and natural regeneration where possible.

Culturally and ecologically central, ʻōhiʻa holds a prominent place in Hawaiian tradition and forest ecology.