When scientists sample the soil, bodies of water, or even the air for DNA, they routinely unmask thousands of tiny mysteries — unique fragments of fungal DNA that don't match any known species.
This DNA belongs to cryptic organisms, often referred to as dark fungi, which like dark matter and dark energy, are simultaneously all around us and yet elude discovery.
Scientists estimate that somewhere between 2 and 12 million species of fungi remain undiscovered.
Their physical structures yet to be seen either because they're microscopic, live hidden within other species, or for other unknown reasons.
The diverse fungal kingdom, which includes everything from baker's yeast to edible mushrooms to foot infections, has long defied assumptions.
For centuries, biologists mistakenly classified them as plants for what they'd argue were good reasons.
Many grow from the soil atop branching root-like networks.
But at the biological level, they're very different.
Unlike plants that harness energy from the sun, fungi eat by decomposing matter or siphoning nutrients from other organisms.
Rather than cellulose, their cell walls are made of chitin — the same material in exoskeletons of insects like beetles and crustaceans like shrimps.
