The Humongous Fungus

This is Armillaria ostoyae. It's larger than the 110-foot long, 200-ton blue whale and occupies about 2,384 acres (almost 4 square miles!) deep in Oregon's Blue Mountains. It's not only the world's largest mushroom, it's also the world's largest known organism. The fungus is believed to be around 2,400 years old, but could possibly be even older, maybe as old as 8,650 years. That would make it one of the oldest living organisms. It grows along tree roots and is quite resilient, having grown for over a millennia. "A team of forestry scientists discovered the giant after setting out to map the population of this pathogenic fungus in eastern Oregon. The team paired fungal samples in petri dishes to see if they fused (see photo below), a sign that they were from the same genetic individual, and used DNA fingerprinting to determine where one individual fungus ended."