Mushrooms Versus Mycelium

The essential part of a mushroom, the Mycel, is usually hidden from our eyes. What we perceive as a “mushroom” is only its transient fruit body.

The mushroom's main body is the mycelium, a network of thread-like structures called hyphae, which live underground or within the substrate (like wood or soil). The mycelium is the organism's true form and is typically hidden from view. 

When mycelium is grown on an agar plate in a petri dish, its network becomes visible as it spreads across the medium. The fruiting body that the mycelium produces is used to release spores for reproduction. This fruit body is temporary and only appears when conditions are right, while the mycelium can persist for years. That's why when you pull up a mushroom in your lawn, it seems to reappear at a later time because the mycelium is still intact underground.