Wednesday 29 May 2019

Picking Mushrooms for Identification

Geopora cooperi - ©M. Kilger

"I desired to know what Mushrooms they had in the Market. I found but few, at which I was surpris'd, for I have all my Life been very Curious and inquisitive about this kind of Plant, but I was absolutely astonish'd to find, that as for Champignons, and Moriglio's, they were as great strangers to 'em as if they had been bred in Japan."--William King's Journey to London, 1699, demonstrating the continuing English suspicion of fungi.

Episode VIII: A New Find

One day, a few years ago, I was picking Morels in a burn and came across a likely-looking 'shrump.

When I brushed the duff off of the top, I was shocked to find something that I had never seen before. Initially, it just looked like a Morel with a bit of dirt on top of it; but, pulling it up revealed it to be something far different.

Immediately, I brushed it as clean as possible, and bisected it to get a better look at its structure. Could this be some sort of bizarrely deformed Gyromitra??

I captured a few images of the mushroom in situ, brushed off, but whole, and bisected. I shot them off to one of the best identifiers with whom I am acquainted, and they pointed me in the right direction to discover which species I had found. This was my first experience with Geopora cooperi, and I learned a good bit from it.

You picked a mushroom that you didn't know!  

We have all seen it, in the online mushroom community, and even sometimes in person: "Why did you pick those mushrooms, if you don't know what they are?"

The answer is very simple: "Because I didn't know what it was, and I need a few specimens to work with for identification."

Realistically, we can take all of the images that we want and note as much information as possible about the environment in which a particular mushroom is growing, and do all of the things right - but still be missing information vital to the identification of that particular mushroom.

There is no substitute for having at least one (and preferably a number of them) specimen in hand.

With specimens in hand you can do many things that are simply not feasible in the field - microscopic inspection of the structures in the mushroom, such as spores, spore-bearing tissue, pileal tissues, etc.; chemical reagent tests; staining/bruising tests; changes in aroma due to temperature; as well as just a very thorough review of the morphology of the mushroom in question.

Why are you killing mushrooms for curiosity?

That's really the first argument that comes up, and its premise is unfounded. 

To rationally discuss the issue, we need to know a little bit about mushroom biology. 

What is a mushroom?

A mushroom is a sporocarp - an organ for developing and dispersing spores. It is, in actuality, a reproductive organ, analogous to a plant's fruit. 

The organism that produces it is the mycelium, which permeates the substrate and gathers energy from the nutrients therein. This organism is not damaged by picking its fruit.

When conditions are right, and all environmental factors are optimal, that mycelium produces fruits - mushrooms - to allow it to share its genes with the rest of the world. 

Those mushrooms produce spores which are dispersed in a number of ways, most commonly on the wind. 

Each mushroom produces hundreds of thousands, if not millions, of spores - each with the capability to germinate into hyphae, and grow into mycelia of their own, repeating this same cycle elsewhere. 

How does picking its fruit affect the mycelium? 

Realistically, it doesn't - no more than picking an apple, or a handful of berries, affects the tree or bush from which they came.

Mushrooms are fruiting bodies - not the life of the organism.

If we were talking about a plant, there are certainly good reasons to leave it in situ, as pulling up a plant often does end the life of that plant, and removes it from the gene pool.

However, fungi are not plants. They are completely different taxonomic kingdoms, and for good reason.

Without digging up the majority of the mycelium, you're doing no damage by pulling a mushroom out of the soil. The mycelium is unharmed, and may actually benefit (very slightly) from the act. We have over 60 years of empirical data to back these conclusions.

But spores are important for next year's mushrooms!

Yes... and no. 

Spores help to establish mycelia in other locations, and those mycelia may eventually provide fruits of their own; but, existing mycelia persist as long as their environment can accommodate them, and produce fruiting bodies whenever conditions are right. 

Moreover, the chances of anyone picking every single sporocarp produced by a single mycelium are fairly slim, especially when considered on a year-over-year basis. 

Even, however, if a person WERE to pick all of the mushrooms, every year, from a single mycelium, those mushrooms are often producing spores, or have dispersed most of their spores, by the time that you find them. By carrying them around with you, you may actually be helping disperse those spores into wind currents which they would have otherwise missed. 

How about food for the animals?

Very few animals use fungi as a staple food. 

Deer are known to nibble the occasional mushroom, and maybe even a few at a time; but their mainstay is vegetation. 

Turkeys seem to be a scourge when it comes to Morels; but, they are more interested in the larvae and insects within them. 

Squirrels are one of the few mammals that have developed strategies to deal with some mycotoxins. They also display storage behaviour, when it comes to fungi, and I cannot even count the number of Russula and other mushrooms that I have seen hanging in tree branches, or stuffed into cubbies in trees, for later squirrely feasts. That said, however, they still prefer nuts and seeds - which are far more nutritive than fungi. 

However, when we get down to microfauna, the base of the food chain, we see mycophagy as a more important food. Slugs, and a number of insects use mushrooms as food and nurseries. These insects also become food for larger fauna. 

However, we also tend to avoid harvesting insect-infested fungi, for the most part, so their food and nursery sources are probably pretty well covered. Certainly not threatened to the point where their species will die out, or become endangered. 

Unfortunately, I have not been able to uncover any research studies done on the topic of fungi as a contribution to the food web; however, our impact on that contribution is most likely minimal. 

If you find such research, please feel free to share them - primary sources, only, please.

How to harvest for identification

A few important things to consider, when harvesting specimens to identify. 

  • Keep the specimens intact and protected.
    If you carry a number of small paper bags for just such an occasion, this can help keep specimens separated and protected. Use a rigid container, such as a bucket, for transporting quantities of specimens for identification.
  • Gather the entire specimen.
    Carefully excavate the base of the stipe, keeping intact any tissue around that base. This tissue, especially in the case of Amanita species, can be diagnostic in itself, and should not be destroyed or lost.
  • Take notes.
    Note the nearby foliage, type of substrate (is there buried wood in that loam? Mulch? mosses? What species of wood is that growing from?), date, weather, location, terrain, etc. Gather as much information as possible.
  • Take pictures.
    For identification, start with a few images of the mushroom in situ - before you pick it. Follow that with images of all aspects of the mushroom, after excavating it. Be especially sure to capture any tissue at the base of the stipe, the point where the stipe attaches to the pileus and lamellae, annulus (if present), and other features. Cross sections or bruised areas also should be captured as completely as you can.
    Make sure that all images are taken in natural light, and do not adjust the images to make them "prettier" - use them as they came. 


The minimal disadvantages, if any, to picking mushrooms that you do not know, and which may just "go to waste" (i.e., become compost) are far outweighed by the knowledge that can be gained by bringing home those same mushrooms to study and identify. 

If you happened to gather a nice bunch, which turn out to be edible and good, then you also have given yourself the opportunity to try them as food, and see how you like them. 

Maybe you'll have to schedule a return trip to pick more of them, after you have added them to your "known mushrooms" checklist. 

In essence, don't pick-shame folks for collecting mushrooms that they have not yet identified. They are doing no harm to anyone or anything, and they are learning from the experience. 

If you choose not to do the same, then that is your own choice. It may slow your knowledge growth, or it may not, but the choice is yours. Don't attempt to shame others into compliance with your choice, when there is no impact beyond your own sensibilities. 

Happy hunting! 


  1. Several BBC television programs I have seen suggested never to take more than 20% of a wild mushroom crop, mainly as a precaution against over-foraging. Prior to learning this, I had been in the habit of picking pretty much all of the crop (Calocybe Gambosa), the result ostensibly being that they failed to return the following year. I'd sure be comforted to know that I wasn't responsible for the death of the mycellium.