Heaviest fungus

The most massive fungus is a single gigantic specimen of Armillaria ostoyae honey mushroom, discovered in the Malheur National Forest, Oregon, USA, which is estimated to weigh somewhere between 7,500 and 35,000 US tons (6,800–31,750 tonnes). Known colloquially as the "Humongous Fungus", it occupies a total area of 965 hectares (2,385 acres), equivalent to 1,350 soccer fields, also making it the largest fungus specimen by area.

The honey mushroom is well known for its glowing surface, caused by bioluminescent bacteria, although most of its tissue is around 1 m (3 ft) underground, in the form of root-like mycelia. This also makes it the largest bioluminescent organism on the planet.

Its age is calculated to be at least 2,400 years old, but it may, in fact, be as old as 8,650 years.

By contrast, the Great Barrier Reef (actually a series of 2,100 interconnected reefs) off Australia is considered the largest living structure; it has been formed over some 20 million years by the skeletal remains of billions of tiny marine organisms known as coral polyps.