The National Wildlife Federation

Donate Donate

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.

Get Involved

   Please leave this field empty

Happening Near You

You don't have to travel far to join us for an event. Attend an upcoming event with one of our regional centers or affiliates.

Learn More
Regional Centers and Affiliates