Lonely Planet Writer

Mysterious disease threatens to wipe out Hawaii’s iconic 'ohia trees

A newly identified disease is threatening to kill off Hawaii’s iconic ‘ohia trees. Known for their bright-red, pom-pom-like blossom, the trees are culturally and ecologically significant, being both part of Hawaiian culture and integral to the archipelago’s endangered native animals.

Ohia blossom.
Ohia blossom. Image by Makuahine Pa’i Ki’i / CC BY 2.0

But a strange disease known as Rapid ‘Ohia Death has wrought devastation across ‘ohia forests on the Big Island of Hawaii, and researchers worry that the disease could spread to the rest of the archipelago.

The disease, which is caused by a fungus called Ceratocystis fimbriata, was first noted in 2010, when worried landowners started calling the US Forest Service with reports of wilting ‘ohia trees that were dying in a matter of weeks. The disease wasn’t identified until 2014, when agricultural researchers discovered the fungus in samples taken from trees in Puna, Hawai‘i. Researchers discovered that the disease had infected half of 6000 acres of forest on the Big Island.

Now they believe the disease has spread, covering as much as 34,000 acres of Big Island forests.

Researchers say the spreading disease could have a wide impact on the rest of the island’s delicate ecosystem. ‘Ohia trees, which grow in the island’s volcanic soil, are particularly important for the water supply because they help soak water into the ground, and native birds and insects feed on the trees’ nectar and hide in their canopy. Due to Hawaii’s extreme isolation, the islands’ endemic species are particularly vulnerable to diseases.

Culturally significant for its myriad uses in construction, decoration and mythology, the ‘ohia tree is one of the most important trees in Hawaii. The Department of Agriculture has instituted a quarantine rule on transport of the trees between islands, and in April lei-makers were barred from entering ‘ohia forests to make lei for the Merrie Monarch Festival, which takes place in Hilo, Hawai‘i.