It’s bigger than an elephant. It’s even bigger than a blue whale. It’s the largest living organism in the world and spans a total of 2,200 acres or about four square miles (yes, you read that right). While it’s biological origins might surprise you, it’s been around between an estimated 1,900 to 8,650 years. It’s known commonly as the “honey mushroom” or Armillaria ostoyae.
Discovered initially in Washington state, the fungus DNA was traced all the way to Malheur National Forest in Oregon. To say this find astonished researchers is a gross understatement. Its size was first recognized while scientists were trying to find the culprit behind the dying conifer trees, which were suffering from severe root rot. This fungus feeds on the roots of these evergreens by drawing their water and carbohydrates, using self-produced digestive enzymes. These thick black tendrils, called rhizomorphs or “shoestrings,” extend out to obtain nutrients over vast distances, which allow it to grow so big and why it is considered pathogenic.
Mushrooms aren’t just the bulbous caps and stems we see reaching up from the ground - that is only a small fraction of their existence. On the surface, you might see two completely different mushrooms distant from each other, but these two mushrooms may belong to the same entity underground. Fungi have an underground communication network that is known as mycelium, usually white (you’ve likely seen this if you’ve ever dug up dirt). These tendrils, which look remarkably similar to our nervous system network, can span miles and are generally an essential factor in the health of a forest.
Currently, scientists are working with this fungus to help prevent further degradation of the forests. Introducing other species of fungi and disease-resistant trees seems to be their method of choice to keep the humongous fungus under better control.