Biggest Fungus Among Us

Oregon is home to what is likely the world's largest living thing

• Mark Cheater
• Dec 01, 2000

Creeping largely unseen through the evergreen forests of eastern Oregon is the world´s largest living organism, a fungus called Armillaria ostoyae. The fungus is at least 2,400 years old and covers more than 2,200 acres--or nearly 1,700 football fields--according to scientists with the U.S. Forest Service who discovered it last summer.

"This fungus lives in a below-ground habitat, spreading very slowly outward from tree to tree along roots or by growth through the soil using special shoestringlike structures called rhizomorphs," says Catherine Parks, a biologist with the Forest Service's research station in Portland.

Previously, the title of world´s largest living thing was claimed by an Armillaria covering more than 1,500 acres in eastern Washington, discovered in 1992. Both these records have a dark side, foresters point out: Armillaria causes a root disease that can eventually kill trees. So for this champion fungus, there won´t be tree cheers.