Largest Organism Found in Oregon

By George Grow

This is Bill White with the VOA Special English

Scientists in the American state of Oregon have found
what they believe is the largest living organism on
Earth. The scientists say it covers an area of almost
nine-hundred hectares.

The huge organism is a fungus that spreads through the
roots of trees in the Malheur National Forest in
eastern Oregon. The fungus is called Armillaria
ostoyae. It is popularly known as the honey mushroom.
The fungus causes Armillaria root disease that
sometimes kills trees.

Until now, the largest known organism was another
Armillaria ostoyae found in the state of Washington in
Nineteen-Ninety-Two. It covered more than six-hundred
hectares of land near Mount Adams.

Scientists with the United States Department of
Agriculture Forest Service and Oregon State University
reported finding the larger fungus.

Catherine Parks is a scientist with the Forest
Service's Pacific Northwest Research Station. She
made the discovery after hearing that many trees were
dying near the Oregon community of La Grande.

The team of scientists used laboratory tests to
confirm the size of the huge fungus. They collected
hundreds of pieces of the fungus and compared them to
each other. Two pieces of fungus are considered the
same organism if they grow together in a glass
container. If the pieces do not grow together, they
are considered different organisms.

Mizz Parks and the other scientists say this kind of
fungus can occupy large areas of a forest and live for
thousands of years. They estimate the fungus in
eastern Oregon is about two-thousand four-hundred
years old. Mizz Parks says the fungus lives
underground and spreads slowly from tree to tree. The
fungus looks like white paint on the roots of infected

Mizz Parks says the fungus also can grow through the
soil using long, thin structures called rhizomorphs.
The fungus sometimes can be observed in autumn on the
ground in a forest. It appears as groups of golden-
colored mushrooms.

The Oregon scientists say the fungus is important in
the natural processes of the forest environment. By
killing trees, it opens up areas in the forest to new
growth. The dead trees also provide food for other
plants and homes for wildlife.

This VOA Special English SCIENCE REPORT was
written by George Grow. This is Bill White.

Voice of America Special English