Oregon’s Hidden Gigantic Fungus Reveals Earth’s Largest Living Organism

Researchers mapped a single Armillaria ostoyae fungus beneath Oregon’s Blue Mountains that spans about 9.65 square kilometers and may be thousands of years old, making it the largest known organism on Earth; the discovery challenges how we define an individual, underscores the fungus as a long-running forest pathogen, and suggests management should focus on reducing impact rather than eradicating it.