Laboratory reports confirm that a disease ravaging Hawaii’s most common native forest tree is spreading across the Big Island.

The state Department of Land and Natural Resources reported Friday an ohia tree in the Laupahoehoe section of the Hilo Forest Reserve was killed by a fast-moving fungal infection known as rapid ohia death. The department said two laboratory tests confirmed an ohia tree was killed by a fungus called Ceratocystis fimbriata.

The loss of the approximately 100-foot-tall ohia shows the disease has spread to Hawaii island’s eastern side, the department said in a statement Friday.

The pathogen causes the crowns of ohia to turn brown and die within as little as a few days to weeks of infecting the tree. The fast-spreading disease has killed hundreds of thousands of trees and is threatening native forests and watershed areas on Hawaii island.

“It’s devastating to look at the forest and the damage rapid ohia death is doing to our ecosystem and our watersheds,” said Steve Bergfeld, Hawaii island branch manager with the state Division of Forestry and ­Wildlife. “That tree is a giant in the forest. It also supports a lot of other plant life and bird life. It was an important part of our ecosystem. These trees have been here for hundreds of years, and to see them go down to a disease like this is really heartbreaking.”

Ohia trees are important to the watershed but also provide a canopy to native plants growing underneath it. Native birds feed off of its nectar, and the tree’s flowers are used to make lei.

Many hula halau decided not to use the lei and adornments from the ohia tree at the Merrie Monarch Festival this year in an effort to stop the spread of the disease.

It has infected nearly 50,000 acres of forest on Big Island, the DLNR said.

The pathogen has killed trees in the South Hilo, Puna, Kau and Kona districts of Hawaii island and has the potential to kill ohia trees statewide, according to the College of Tropical Agriculture and Human Resources at the University of Hawaii at Manoa. The disease was found in Puna in 2014.

State and federal government agencies and conservation organizations are working together to prevent further spread of the disease.

The U.S. Department of Agriculture has been testing tree samples from other islands; no infected trees have been found.

In August the U.S. Department of the Interior directed $497,000 in federal funding to help combat rapid ohia death in Hawaii.

Bergfeld said the next step after discovering the tree will likely be removing it from the forest and covering it in tarp so no insects can spread the disease.

The disease can be spread by beetles boring into contaminated wood. When boring, the beetles create a powder that can contain the rapid ohia death fungus. The powder can be spread by the wind.