The largest living organism in the world is a fungus in Oregon, United States.
Why it is true
The fungus Armillaria ostoyae, in Oregon, covers about 9.6 square kilometres and is estimated to be between 2,400 and 8,650 years old. Most of the organism is underground, in the form of filaments called hyphae, and only occasionally appears on the surface.
Source: US Forest Service
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