Fact: The largest living organism in the world is a mushroom.
We all know the blue whale is big, but we’ve been living a lie. At 30m long and weighing in at 200 tonnes, a fully grown whale pales in comparison to the might of natures forgotten beasts – fungi.
This record-breaking fungus is specifically the genus Armillaria – otherwise known as honey fungus on account of their sweet taste. In 1998 scientists discovered a single colony of Armillaria ostoyae that covered a massive 2,300 acres (or 1,665 football pitches) across the Rocky Mountains.
The secret to Armillaria’s size is the way it spreads. Fungal cells send out long, simple threads called rhizomorphs, which seek out new food sources. Only once a food source is identified does the rhizomorph grow more complex structures called hyphae, which break down dead material, grow toadstools above ground and reproduce. The simplicity of rhizomorphs means they are quick and easy to produce, which allows them to travel huge distances underground while remaining connected to the rest of the fungus.
This spreading behaviour creates a network of genetically identical cells covering a huge area, that can still communicate with one another and work together to achieve a common goal. In other words, this network is classed as a single living organism.
This astounding fungus is not just massive, it’s old too: between 3,000 and 8,000 years old in fact, making it also one of the oldest living organisms ever discovered. I never thought that a mushroom would make a blue whale look stupid, but here we are.
‘Another one of Mr Shaunak’s Little Bites of Science’
Image under Creative Commons License