#agar

If you cultivate a mushroom in a petri bowl on agar, its actual “shape” becomes visible. The essential part of a mushroom, the Mycel, the mycelium (the organism's true form) is usually hidden from our eye.

Mycelium, a network of thread-like structures called hyphae, which live underground or within the substrate (like wood or soil).

What we commonly recognise as a 'mushroom' is actually just the fruiting body, which the mycelium produces to release spores for reproduction. This fruit body is temporary and only appears when conditions are right, while the mycelium can persist for years.