Mushroom Identification: In-Depth Guide

Fungi are fascinating and diverse organisms. They range from microscopic yeasts and molds to vast underground networks spanning hundreds of acres. However, probably the most recognizable features of certain fungi are mushrooms.

Humans have a special relationship with mushrooms. We have used them for nutritional and medicinal purposes for thousands of years. Many varieties are healthy and delicious, while certain species have powerful therapeutic properties.

But mushrooms also have a dark side. Although some can nourish and heal, others can be deadly poisonous. Therefore, mushroom identification is essential for any would-be forager to learn.

Before heading into the countryside, it is crucial to understand how to identify edible and poisonous mushrooms correctly. Here is all you need to know.

Mushroom Identification: Deadly or Delicious?

There are numerous cases of mushroom poisoning every year, most of which result from incorrect identification when foraging for edible or hallucinogenic species.

Consuming poisonous mushrooms can cause various reactions, from gastric upsets to nervous system disorders, and occasionally, death. Therefore, anyone who wishes to eat wild mushrooms must know how to identify them accurately.

Unfortunately, many poisonous mushrooms look similar to those that are safe to ingest. For example, deadly Amanita species can look much like edible field mushrooms to the untrained eye. Young amanitas may also be mistaken for puffballs due to their egg-like appearance.

Furthermore, people often confuse false morels (Gyromitra species) with true morels (Morchella species). It is also easy to mistake poisonous jack o’ lanterns (Omphalotus olearius) for chanterelles (Cantharellus species), and so on.

Little brown mushrooms (LBMs) and little white mushrooms (LWMs) are the most challenging to identify. Therefore, individuals foraging for psychedelic Psilocybe species may inadvertently consume poisonous fungi, such as the funeral bell (Galerina marginata).

So, how can you identify mushrooms safely and avoid these dangerous look-alikes? Let’s take a closer look.

How to Identify Mushrooms

It can be challenging to distinguish between edible and poisonous mushrooms. However, it is a vital skill for anyone planning on harvesting mushrooms in the wild.

The best way to learn is by training with a professional mycologist. They will be able to explain how to identify mushrooms in general and the nuances of the local area.

Look for guide books with high-quality color images, detailed descriptions, and discussions of possible look-alikes.

A reliable, up-to-date field guide is the next best option. Look for books with high-quality color images, detailed descriptions, and discussions of possible look-alikes and confusion species. It is possible to purchase handbooks for specific regions and more general guides. There is also a wealth of information online.

The following is an overview of some of the methods that experts use to identify mushrooms. It is not intended to replace official training, and individuals who gather wild mushrooms do so at their own risk.

Season

Many mushrooms are in season during fall when heavy rainfall is common and the earth is damp, providing ideal conditions for fungal growth. However, some species appear during spring, and others survive right through the cold winter months.

Learning which mushrooms are in season at different times of the year can often be the first step toward identification.

Habitat

Different mushrooms prefer different growing conditions. Some have an affinity for open grassland, while others prefer heavily wooded areas.

The material that the mushrooms are growing on is also a critical factor. Are they on soil, wood, or leaf litter? Are they growing close to a particular type of tree?

Many mushrooms form symbiotic relationships with a specific tree species. Therefore, some experts consider tree identification to be an essential skill for mushroom identification.

Habit

A mushroom’s habit refers to how it grows. This usually means whether it is alone or in a large cluster, forming a ‘fairy ring’ or scattered, and so on.

Cap

The cap is one of the most distinctive features of a mushroom, and its appearance plays a crucial role in identification. Pay attention to its size, shape, color, and texture. Of course, it is important to note that these features can change significantly as a specimen ages.

Furthermore, not all caps have a classic mushroom shape. They can also be described as brackets, rosettes, vases, clubs, balls, teeth, coral, columns, cups, and jelly.

Spore-Bearing Surface

The spore-bearing surface is usually, but not always, underneath the cap. It houses the structures that produce spores and allows the fungus to reproduce.

Many mushrooms have gills, and these can be of various colors. Another critical factor is whether the gills are attached, unattached, or run into the mushroom’s stalk (decurrent gills). Finally, it is useful to note whether the gills are straight or wavy and how well-spaced they are.

Other types of spore-bearing surfaces include pores, ridges, tubes, and spines. Once again, it is vital to consider their color, texture, size, and spacing.

Stalk

The stalk, sometimes known as the stipe, is the structure that supports the cap. Its color, length, diameter, shape, and texture are all helpful identification tools.

Some, but not all, stalks also have a ring and a volva (see below). These structures are often one of the most reliable ways to distinguish between edible and poisonous mushrooms. For example, they are a common feature of many Amanita species.

Ring

The ring, or annulus, is a remnant of a structure known as the veil. It covers the spore-bearing surface in young mushrooms and breaks away as they mature. Some mushrooms retain their veil as a collar-like ring on their stalk while others do not.

Volva

The volva is the remnant of a universal veil that covers the whole of some young mushrooms as they emerge. It ruptures as the mushroom grows but may remain as a cup-like structure at the base of the stalk.

Bruising and Staining

Some mushrooms bruise or stain a distinctive color when rubbed, crushed, or cut. For example, many Psilocybe species are known for bruising greenish-blue when damaged. Other mushrooms may bruise blue, red, yellow, or brown, further assisting identification.

Spores

The spores’ color is one of the best ways to identify mushrooms. Sometimes, it is possible to see spores staining the gills or stalk of a mushroom. However, it is also advisable to take a spore print.

How to Spore Print a Mushroom

To spore print a mushroom, take a piece of black paper and a piece of white paper and tape them together. Flip them over so the tape is underneath, and place a mushroom cap, spore-side down (remove the stalk first) in the center.

Cover the mushroom cap with a glass and leave it for 12–24 hours. This should be long enough for a distinct spore print to form. Using both black and white paper means that the spores should be visible no matter what color they are.

Taking a spore print is often a reliable identification method. However, expert mycologists may take things a step further by putting the spores under a microscope for analysis.

Staying Safe

Below are a few more tips for identifying mushrooms confidently and how to consume them safely:

Beware Look-Alikes

As we mentioned earlier, some poisonous mushrooms look very similar to edible ones. Therefore, individuals must learn the possible look-alikes for any species they intend to consume and how to spot them.

Identify Every Specimen

Sometimes, poisonous and edible mushrooms grow side by side. Therefore, it is necessary to identify every single specimen before consumption.

Save Samples

Collect some additional samples and keep them aside. If somebody gets sick after eating the mushrooms, an expert can identify them and ensure that the patient receives the correct treatment.

There Are No Shortcuts

There is an abundance of folklore regarding how to tell edible mushrooms apart from poisonous ones. However, many of these ‘shortcuts’ are inaccurate and should be ignored.

Start Small

Whenever consuming a mushroom for the first time, try a tiny amount first and wait 24 hours before eating more. Some people can react badly, even to edible species, so this is a crucial step.

Pay Attention to Storage and Preparation

Mushrooms can go bad quickly, so it is best to consume them fresh. If necessary, store them in a refrigerator wrapped in paper rather than plastic to keep them at their best for longer. Throw away any old, damaged, discolored, soggy, or smelly specimens.

Store mushrooms in a refrigerator wrapped in paper rather than plastic to keep them at their best for longer.

It is also important to cook mushrooms well before eating them to destroy any harmful microbes inhabiting them.

Finally, pay attention to the guidelines for specific varieties. For example, consuming inkcaps (Coprinopsis atramentaria) with alcohol can cause a severe reaction.

If in Doubt…

One of the most valuable sayings in mycology is “if in doubt, throw it out.”

If there is any question about a mushroom’s identity, throw it away immediately. Better still, unless you are 100% certain, leave it for the other wildlife to enjoy instead. It simply isn’t worth the risk.

Final Thoughts on Mushroom Identification

Mushroom hunting can be a fun and exciting pastime. However, it can also be dangerous, especially when it comes to consuming one’s finds. Many poisonous species can look similar to edible ones, and some of them are potentially deadly.

Therefore, foraging for wild mushrooms should be left to the experts, and novices should exercise extreme caution. There are plenty of tasty varieties available in stores, and medicinal mushroom supplements are becoming increasingly popular. With such a vast array of options, there is no need to take unnecessary risks.

Want to enjoy forest-fresh mushrooms without the risk? Why not try growing your own?

• How to Grow Mushrooms: Beginner’s Guide
• How to Grow Magic Mushrooms
• Magic Mushroom Spores: Beginner’s Guide