Yes, and at 2,200 acres in size it will take some beating. We’re talking about a Honey Mushroom (Armillaria Ostoyae) that lives in the Malheur National Forest in Eastern Oregon.

Apart from a few mushroom heads, the bulk of the fungus lives underground so it’s hard to envisage it’s size. But scientist have tested samples from various locations and confirmed that it is all one organism. It takes the form of a mycelial mat - effectively a giant network of single-celled filaments or tentacles that take water the nutrients from the surrounding soil and roots.

The fungus has been estimated at 2000 years old, but it could be far older than that.