The biggest mushroom in the world, armillaria ostoyae, also known as humongous fungus. The mushroom covers 2,385 acres at Malheur National Forest, Oregon. It was estimated to be 2,400 years – 8,650 years old now. It attached itself to the tree roots via hyphae- fine filaments that tangle together and leak digestive enzymes. The mushroom will feed off the tree roots and in the process killing the trees it’s attached to. The stable environment of the forest has enabled the fungus to spread as far as it has. The giant mushroom has again sparked what constitutes an individual organism. It is agreed that if a being has a set of cells that are genetically identical and communicate to each other, it can be classed as one single organism.