When you step onto the trail during a Club campout, an entire world is at work beneath your boot. That is not a tree root or an earthworm. A white web, as thin as a strand of hair, spreads across meters and meters of soil. That is the body of a fungus, and it belongs to one of the strangest and least known kingdoms of creation.
For a long time people thought a fungus was a kind of plant. It stays put, sprouts from the ground and looks like a vegetable. But scientists discovered that fungi are as different from plants as you are from a bean stalk. They earned a kingdom all their own, the Kingdom Fungi, alongside animals and plants.
In this article you will get to know that hidden kingdom: the mycelium, the mushrooms, the spores, the cleaners that recycle dead matter, the yeast in bread, the penicillin that saved millions of lives and the secret partnership that feeds the forests. And, at the end, the record: the largest living thing ever found on Earth is a fungus.
Neither plant nor animal: a kingdom of their own
In school you learned to divide living things into plants and animals. Then came the bacteria. Fungi were left in a corner, without much of a place, until scientists realized they deserve a whole kingdom just for themselves: the Kingdom Fungi.
Why aren't they plants? Plants make their own food from sunlight, through photosynthesis. A fungus does not do that. It has no chlorophyll, it is not green and it does not use light to eat. Instead, it digests its food on the outside: it releases substances into the environment that break down the matter around it, and then it absorbs the result. It is as if you poured stomach acid onto your plate and slurped up the soup that formed.
Curiously, at the chemical level a fungus is closer to you than to a tree. Its cell walls are made of chitin, the same material as the shells of beetles and shrimp. A mushroom and a cockroach share an ingredient that lettuce does not have. Creation is full of these surprises when you look closely.
The mycelium: the hidden body, and the mushroom is only the fruit
Here is the biggest misunderstanding about fungi: many people think the mushroom is the whole fungus. It is not. The mushroom is only the part that shows up to reproduce, like the apple on an apple tree. The real body stays below, invisible.
That body is called the mycelium. A network of ultra-thin white threads, called hyphae, branches through the soil, through rotting wood, inside a fallen leaf. In a handful of forest soil there can be kilometers of tangled hyphae. The mycelium is the part that eats, grows and lives all year long.
When the time comes to spread the species, the mycelium pushes a mushroom upward. Under the cap sit the gills, which release millions of spores, tiny specks as light as smoke. The wind carries them, the rain spreads them, and wherever a spore lands in a damp place a new mycelium is born. That is why a mushroom appears overnight after the rain: the body was already there the whole time, it just needed the fruit to sprout.
On a Specialty hike, it is worth stopping to observe a mushroom without pulling it up. Never eat a wild mushroom. Many are poisonous, and some of the most dangerous ones are nearly identical to the edible kinds. Looking, photographing and drawing is the safe way to study them.
The cleaners of creation
Think about how much dies in a forest every year: leaves, branches, trunks, animals, rotting fruit. If nothing removed that material, the world would turn into a mountain of leftovers in no time. Fungi are the cleanup crew that prevents this.
They are the planet's great decomposers. The mycelium works its way into dead wood and fallen foliage and breaks it down into smaller and smaller pieces, returning to the soil the nutrients that were locked up in there. Without fungi, carbon, nitrogen and minerals would stay trapped inside the trunks, and new plants would have nothing to feed on.
There is even a type of matter that almost only fungi can digest: lignin, the tough substance that keeps a tree standing. Few creatures in the world can handle it. Fungi can. They close the cycle of life, turning death back into fertile soil. It is a silent recycling happening beneath your feet at this very moment.
Read alsoLiving soil: the handful of earth that feeds the worldFrom bread dough to the medicine that saved millions
Not every fungus lives in the forest. Some work in your kitchen. Yeasts are microscopic, single-celled fungi, and one of them makes bread rise. When the baker mixes yeast into the dough, the yeast eats the sugar in the flour and releases carbon dioxide. Those gas bubbles are what make the dough puff up and the bread turn soft. The same family of yeasts ferments drinks and helps cheeses mature.
Another fungus changed the history of medicine almost by accident. In 1928, the Scottish scientist Alexander Fleming came back from vacation and found a greenish mold growing on a dish he had forgotten in the laboratory. Around that mold, the bacteria had died. The fungus was of the genus Penicillium, and the substance it released was named penicillin.
Penicillin became the first widely used antibiotic and went on to save millions of people from infections that used to kill easily. A common mold, the kind that shows up on a forgotten orange, held a medicine that changed the world. Remember that medicine is a matter for doctors: antibiotics only with a prescription and professional guidance, never on your own.
The secret internet of forests and the lichens
Beneath almost every healthy forest there is a partnership that few people know about. The roots of the trees connect with the mycelium of the fungi in an alliance called mycorrhiza, which literally means fungus-root.
It works like this: the fungus wraps itself around the roots and stretches its ultra-thin threads much farther than the root could reach on its own. It seeks out water and minerals from the soil and delivers them to the tree. In return, the tree pays with the sugar it makes in the sunlight. Both come out ahead. A tree with a good fungal partnership grows stronger, and a whole forest can be linked by this underground web, trading nutrients from one plant to another.
Fungi also form a second famous partnership: the lichens. That gray, green or orange crust you see stuck to rocks, walls and old trunks is a fungus living together with an alga. The alga makes the food with light, the fungus offers shelter and moisture. Together, they survive in places where nothing else grows, from the desert to the icy mountaintops. Where you saw only a stain on the rock, there is a society of two different beings working side by side.
The largest living thing on Earth is a fungus
When someone asks what the largest living thing in the world is, the expected answer is the blue whale or the giant sequoia. Both are enormous. But the record belongs to an organism that almost no one can see in full: a fungus.
In the Malheur National Forest, in the eastern part of the state of Oregon, in the United States, there is a single fungus of the species Armillaria ostoyae, known as armillaria or honey mushroom. Its mycelium spreads through the soil across about 9.6 square kilometers, an area bigger than a thousand soccer fields. Laboratory tests confirmed that all of it is a single, genetically identical individual, linked together underground.
And it is ancient. Judging by its growth rate, scientists estimate that this fungus is at least about 2,400 years old, and it may be close to 8,000 years old. It was already growing there long before the cities you know existed. In autumn, when it sends up its honey-colored mushrooms among the trees, that is the only visible clue to a giant that spends almost its entire life hidden.
This record fits with a truth about fungi: they are a vast and almost unexplored kingdom. Scientists estimate that there are between 2.2 and 3.8 million species of fungi on Earth, and to this day only a small fraction, something around 150,000, have been described and given a name. The overwhelming majority remain unknown, waiting to be found.
The God of details and our stewardship
For the Pathfinder, looking at nature goes beyond scientific curiosity. It is a way of knowing the Creator through what He made. The psalmist wrote, in wonder: "How many are your works, Lord! In wisdom you made them all; the earth is full of your creatures" (Psalm 104:24, NIV). A whole kingdom of millions of species, most of them invisible to the naked eye, fits that description well.
In the creation account, in Genesis 1, after each day of work it is written that God saw that it was good, and at the end that everything was very good (Genesis 1:31). The recycling system hidden in the soil, the partnership between fungus and root, the mold that became a medicine: it is all part of a world designed with care, including in the corners no one sees.
From the very beginning, human beings were given the task of caring for this world. Caring for creation goes beyond admiring the pretty scenery; it means respecting even the web of fungi beneath the trail, not destroying it for fun, learning before touching. A good idea for a Unit meeting is to head out into the field with a magnifying glass and a notebook, record the fungi, lichens and mushrooms you find, and give thanks for the Creator who takes such care with the hidden details. You can fit this outing into the Club's meeting plan.