What Are The Key Parts Of A Mushroom?: A Deep Dive Into Anatomy

Did you know that according to experts there are roughly 140,000 different species of mushrooms on Earth? What’s crazier still is that we've only discovered about 10% of them!

But while there are many different types of mushrooms in the wild, they all have certain key parts, structures and anatomical features in common that we need to know about.

After all, understanding the anatomy of a mushroom can help you better understand how they grow, how they carry out their functions, what they need to thrive, and which parts of them are edible.

So, if you’re interested in exploring more about all the key parts of a mushroom, keep reading!

Mushroom Anatomy 101: A Quick Overview

Most mushrooms & fungi have two main parts: the underground mycelium and the above-ground sporophore or fruiting body. Let's talk about both of them in a bit more detail.

Mycelium

The mycelium is the vegetative underground half of the mushroom and it's responsible for the growth and survival of the mushroom.

It looks like a network of white or yellowish threads/roots and it can grow to be quite large - researchers have even found some that are 2,400 years old and weigh as much as 100 tons!

This vast complex of fibres spreads underground in search of essential nutrients and even connects fungi together.

Unlike plants that have chlorophyll for making their own food, mushrooms need to rely on mycelium to absorb vital nutrients from the surrounding decaying and dead organic matter in the soil.

Interestingly, it can also stay inactive/dormant for several years until the environmental conditions are more favourable for fruiting and distributing spores.

Fruiting body

The sporophore (or fruiting body) is the reproductive part of the fungus and it's what we typically think of when we picture a mushroom.

Depending on the species, it’s also sometimes edible and is where most of the helpful compounds of medicinal mushrooms are found.

The sporophore consists of the main parts of the mushrooms such as the:

Cap
Gills
Stape
Annulus
Volva

This part of the mushroom often grows above ground level or on the surfaces of other hosts, and its main function is to make and spread mushroom spores so the mushroom can reproduce.

The Main Parts Of A Mushroom And Their Functions:

Now that we know the basics of mushroom anatomy and mushroom structure, let's take a more in-depth look at the main structural parts of a mushroom and their functions.

The Cap

The cap (also known as pileus) is the uppermost part of the mushroom and it can be:

Convex
Flat
Umbrella-shaped
Conical
Depressed
Ovate

But what does the cap of the mushroom do?

Well, much like how umbrellas are used to protect us from the rain and sun, the mushroom cap protects the gills, spores, and other parts of the mushroom from harsh weather conditions and the heat of the sun.

The surface of the cap can be smooth or have different types of textures like scales, warts, or gills (more on this later). The texture and colour of the cap vary depending on the species as well as the developmental stage of the shroom.

The Gills

Gills are thin sheets of flesh that hang from the underside of the mushroom cap and they're where spores are produced.

They can be free, meaning they're not attached to the stem, or they can be fused to it. Gills can also have different shapes such as being:

Radial
Forked
Spoon-shaped

This makes them especially useful for the identification of different mushroom species. For example, humans have been successfully identifying poisonous species of mushrooms like the Destroying Angel, Spring Amanita, and Clitocybe Dealbata for centuries based on their characteristic white gills.

Still, it’s important to note that not every type of mushroom has gills. Some like Lion’s mane instead have needles or teeth.

The Spores

Spores are the unicellular, reproductive cells of the mushroom and are produced in the gills. In essence, it possesses all the necessary genetic material needed to produce new shrooms.

Near the end of each mushroom’s life cycle, they distribute their spores using the wind, water, humans, or other animals to disperse them. And when they land on suitable moist, warm, and shaded areas, they germinate.

Scientists are able to use the size, shape, and colour of spores to accurately identify mushroom species.

The Annulus

The annulus is a ring-like structure that's sometimes present on the stems of certain mushroom species. It’s the remnants of the partial veil, which is a membrane that covers the gills when the mushroom is still young to provide additional protection for the spore-forming gills.

As the mushroom grows and the cap expands, this membrane breaks and leaves behind this ring-like structure.

Some people often use the annulus position, shape, and type for the classification and identification of different species of mushrooms.

The Stape

The stape is the stalk or stem that holds up the mushroom cap. It can be short or long, and it can be the same colour as the cap or a different one.

The surface of the stape can also be smooth or have different types of textures like scales, warts, or gills.

Its main purpose is to help with the dispersal of spores by elevating the cap and gills from ground level for the fungus to be able to distribute its reproductive spores effectively for the animals or the wind to scatter them.

Mushrooms that have stapes or stems are often referred to as “stipate” and their specific shape, texture, and size can also be used to help in identifying certain mushrooms.

The Volva

The volva is a sac-like structure that's found at the base of the stape and it is formed by the remnants of the universal veil. This is a membrane that covers the entire mushroom when it's still young.

As the fungus grows, this membrane breaks and leaves behind this sac-like structure. Depending on the species, the volva can be small and barely noticeable or it can be large and very prominent.

Crucially, a large volva is a useful distinguishing feature of poisonous shrooms such as those belonging to the Amanitaceae subspecies.

The Mycelium

As we’ve mentioned before, the mycelium is the vegetative part of the mushroom and it's a mass of white, thread-like fibres that make up the underground body of the fungus.

It's responsible for the absorption of nutrients and water and it also helps to connect different fungi together.

The Hyphae

Hyphae are similar to mycelium, but they're thinner and more branched out. They also have septa, which are cross-walls that divide the cells, and these help the fungus to move nutrients around more efficiently.

FAQs:

Still have questions about mushrooms? Here are some answers to a few commonly asked questions:

Which Parts of a Mushroom Are Normally Eaten?

Mushroom caps and stems are the most commonly eaten parts of a mushroom, but some people also like eating the gills and even the mycelium.

Bonus Tip: If you’re looking to harness the power of mushrooms and add some incredible medicinal varieties to your daily routine, consider browsing what mushroom-based products our friends at LifeCykel, Teelixer, and SuperFeast have to offer.

Do Mushrooms Have Roots?

Mushrooms don’t have true roots, but they do have a root-like structure called mycelium which does pretty much the same thing as plant roots.

The mycelium helps the mushroom to absorb nutrients and water, and it also helps keep it anchored to the ground.

Are Mushrooms Classed As Animals?

Mushrooms are actually classified as fungi, which is a separate kingdom from plants and animals entirely.

Why Is It Called Mushroom?

The word “mushroom” actually comes from the French word mousseron, in reference to moss (mousse).

What Is The Skin Of A Mushroom Called?

The skin of a mushroom is called the “cuticle”, and it's a thin layer of tissue that covers the surface of the cap or stem.

Is It OK To Eat Mushroom Skin?

Yes, if a mushroom is edible, it’s completely safe to eat the skin. In fact, you should refrain from peeling away the skin from edible mushrooms as the cuticle can contain some healthy and tasty nutrients.

How Can You Tell A Good Mushroom?

There are a few things you can look out for to make sure you’re picking a good mushroom.

First, check to see if the mushroom is bruised or broken. If it is, it’s probably not going to be very good.
Second, take a sniff. If it smells bad, it probably is bad and will taste terrible.
And finally, give it a little squeeze. Fresh mushrooms always feel springy, firm, light, and plumb. If it’s slimy, soggy, or floppy, then it has probably already started to decompose and you shouldn’t eat them.

The Takeaway

Mushrooms are incredible organisms that provide endless benefits to humans, plants, animals and the world around them.

The anatomy and structure of mushrooms can vary wildly with some species completely unrecognisable from others!

Medicinal mushrooms (e.g. chaga, turkey tail, reishi, tremella, shiitake, maitake etc.) are a particular point of interest here at The Bircher Bar as their impact on human and animal health can be quite remarkable.

Always remember, if you choose to forage and gather your own mushrooms - make sure you are 100% confident in identifying the species before eating as some can be incredibly toxic!

Finally, for an even deeper dive on mushroom structure and anatomy - let Professor Dave show you the ropes in this awesome video below:

Medicinal Mushrooms Gourmet Mushrooms