February 20, 2026 | Source: Chelsea Green Publishing

How do mushrooms grow? How do they eat, reproduce, or spread? What exactly is a mushroom? All of these answers and more can be found in the intricate, web-like fiber found underneath these fungi: the mycelium.

Understanding this “vegetative” part of the fungus is key to understanding the whole system. 

The following is an excerpt from In Search of Mycotopia by Doug Bierend and has been adapted for the web.

What Is A Mushroom?

Whether you’ve tripped on them or over them or just enjoy them on your pizza, most encounters with fungi involve mushrooms. The utterly common supermarket “button” variety may spring to mind, or perhaps the pale little parasols common to fields and suburban lawns.

But mushrooms are a universe unto themselves, expressing every imaginable (or, as one soon discovers, often unimaginable) form and texture.