What’s the largest organism in the world? I know what you’re thinking. Andre the Giant, a massive human being over 7 feet tall and 500 pounds. But no, not Andre.
Elephants are big, sure. And blue whales are 100 feet long and weigh 20 tons. Still no. And not even close.
The answer is, well, it depends.
The tallest organism in the world is a redwood tree named Hyperion that reaches 380 feet in height. That’s taller than the Statue of Liberty.
However, if we’re talking biomass, that is the total dry weight, then the heaviest organism in the world is an 80,000-year-old tree named Pando that tips the scale at 13 million pounds. That’s 40 blue whales.
You might be thinking a tree like that would be the size of the Empire State building. It’s nothing like that. Pando is a quaking aspen that lives in Utah. It’s not a massive tree, though. It’s an estimated 50,000 individual trees. Sounds like cheating, but it’s not.
A quaking aspen sends up new shoots, or suckers, from its expanding root system. We see this type of growth in our landscape, just not to this extent. Suckers are clones of the parent plant.
The span of Pando’s genetically identical trees covers 104 acres. That’s 80 football fields. Based on DNA testing, this forest is one organism. In autumn, the entire forest will drop its leaves in unison.
If, however, we include water in our calculation, the largest organism in the world lives isn’t a tree or a whale or a world-class wrestler. It lives in Oregon and covers just under four square miles. That’s about 1,900 football fields. This prize goes to Armillaria solidipes. Otherwise known as the honey fungus.
The body of a fungus is a collection of thread-like structures called mycelia. Your jack o’ lantern will be filled with mycelia when Halloween is over, although not from the honey fungus.
Many fungi are saprophytic, feeding on dead organic matter like rotting logs and fallen leaves.
Others are symbiotic, such as mycorrhiza, and grow on roots, which helps trees absorb water and nutrients in exchange for carbohydrates.
The honey fungus, however, is parasitic. It will infect trees causing a fatal disease known as white rot. This typically isn’t a problem we see in the landscape but more often in forests.
On a recent trip to the Smoky Mountains, we came across a colony of what looked like honey mushrooms. Mushrooms are fungal fruiting bodies like apples on an apple tree. Instead of seeds, mushrooms produce spores.
Honey mushrooms grow in clusters. In this case, they were crowded around a stump. These mushrooms are edible. However, when it comes to harvesting mushrooms, I’m really only certain about chanterelles and lion’s mane. And while honey mushrooms are considered delicious, there are look-alikes that are toxic. I’m not a mushroom expert or a risk taker.
I started with a mushroom identification app. I’ve found this app to be quite helpful. However, it will remind the user multiple times not to eat a mushroom based on the app. Find an expert, it says. Not me.
The warning was duly noted. The app identified my picture as a honey fungus. So we were on the right track.
Identifying features of a honey mushroom include a ring around the stem where the veil breaks, gills beneath the cap that attach to the stem and scales on top of the cap.
Further investigation would require a spore print. This requires removing the cap and placing, gills down, on a piece of paper. After 24 hours, the paper will be dusted with spores. In the case of honey mushrooms, the spores are white.
While I was quite certain we could have made a meal back at camp, my low-risk nature decided to leave them for other hikers to enjoy.
Many of them probably had no idea it was the same species of one of the largest organisms in the world.