What Are Mushrooms? A Comprehensive Guide

What Are Mushrooms? A Comprehensive Guide

Have you ever wondered what mushrooms are? Whether you're a culinary enthusiast or a curious nature lover, mushrooms are fascinating organisms. In this guide, we'll delve deep into the world of mushrooms, their types, uses, and nutritional benefits.

What Are Mushrooms? An Overview

What is a Mushroom?

Is it a plant? An animal? Something else? What does it eat? How does it fit into the web of life?

Mushrooms are neither plant nor animal, but can share certain traits with both, and are wonderfully unique the rest of the time. Mushrooms may often look a bit like a plant, but where the cell walls of plants are made of cellulose, the cell walls of mushrooms are made up of chitin, the same material that makes up the armor of many insects and arthropods!

Mushrooms grow from certain types of fungus, a fascinating form of life that has existed on earth for nearly a billion years.

A mushroom is technically actually just one part of a larger fungal organism, the fruiting body (or “sporophore” if you really want to get technical) that helps the fungi propagate by sending out reproductive spores. But since it’s the most visible part, and the one we’re most interested in, we can usually get away with referring to the entire organism as a mushroom.

Fungi are everywhere, from the ash-covered slopes of volcanoes to thousands of feet below the surface of the ocean! They play a vital role in every ecosystem’s life cycle, helping to break down complex organic chemicals into simpler molecules and returning them to the environment. Humanity has catalogued over 100,000 species of fungi - about 14,000 of those produce what we’d call mushrooms - but scientists estimate there may be as many as 1.5 million or more members of Kingdom Fungi.

What Are Mushrooms? a. introduction

OK, but what is a fungus really? How do mushrooms eat and grow?

Unlike animals, who eat food and break it down into energy inside their digestive system, or most plants, which photosynthesize sunlight into energy, fungi absorb nutrition from their surroundings by secreting enzymes that break down their food source into simple molecules.

Multicellular fungi like mushrooms “eat” by sending out thin, nutrient-absorbing filaments called hyphae into their food source, gradually creating an interwoven network of hyphae called mycelium. Mycelial networks expand through the soil to maximize their nutrition absorption, and can be vast indeed. One such network, a honey mushroom in Oregon, has been found to occupy some 3 square miles of forest and weigh as much as 35,000 tons, making it the single largest living organism on the planet. Scientists estimate it may be as much as 8,600 years old, making it one of the oldest known living things as well.

For just about every living thing there is a fungus that has evolved to break it down into soil, even other fungi. Many commonly grown mushrooms specialize in breaking down animal-based nutrient sources like manure, or plant-based nutrients like wood.

Some fungi form mutually beneficial relationships with other life forms, others are microscopic predators. Some fungi have valuable nutritional and medicinal properties, and other species are toxic or the source of dangerous illnesses for plants or animals. Fungi range from the single-celled yeasts who make wine and bread possible, to vast underground organisms that shape the very landscape.

What Are Mushrooms? b. How mushrooms reproduce

Fungi reproduce in a dizzying variety of ways, both asexual and sexual, in order to produce seed-like genetic packages called spores, usually in great numbers. Many fungi (typically belonging to the order Agaricales, but not always) project their spores contained within gill-like structures beneath the familiar umbrella shape we know as mushrooms.These tiny spores can then be spread by wind, water or a passing animal.

Types of Mushrooms

Edible Mushrooms

Question: Can you eat mushrooms?
Answer: There are hundreds of edible species of mushroom, prized around the world for their flavor and nutrition value. Shiitake, Oyster, Portobello, Hen of the Woods, and Button mushrooms are a few of the more popular types of edible mushrooms. 

Poisonous Mushrooms

Not all mushrooms are safe to eat. Several dozen species are extremely poisonous and can be lethal if ingested. Some poisonous species, like the Death Cap (Amanita phalloides), can closely resemble edible mushroom types. Always use caution when foraging wild mushrooms. Take care to clearly identify any mushroom and be absolutely sure it is a type that is safe to eat before you cook it up for dinner. A wrong guess could have serious consequences.

Uses of Mushrooms

Beyond the important ecological role mushrooms naturally play, humans use many types of fungi for many purposes, from food and fermentation to pigments, spiritual practices and traditional medicine. Modern scientific research has also discovered that certain fungi have potential applications in creating environmentally sustainable building materials, cleaning up toxic spills, and pest control, among many other beneficial uses.

Nutritional Benefits

As a low calorie, low fat source of fiber and important nutrients, edible mushrooms are a health-conscious and flavorful addition to many diets. Many mushrooms are prized around the world for a variety of healthful qualities, and mushrooms are frequently found in nutritional supplements and traditional medicines.


Mushrooms are fascinating organisms with incredible variety and great importance to humanity and the planet. From culinary and medicinal uses to cutting edge scientific research, mushrooms will continue to be a big part of your world.