There are lots of different species of wild mushrooms in this world: 10,000 or so by conservative estimates, and probably many more, and millions species of fungi overall (1.5+ million if you’re an optimist…because you know, we’ll eventually get to all of them…and 5.1+ million if you’re a pessimist or simply like impressing non-mycophiles with huge numbers). This human-centric-trauma-inducing fact makes wild mushroom hunting and fungus identification one of those hobbies that you can spend a lifetime pursuing and continue learning new things endlessly, which is one of the many reasons I adore it.
In my current home state of North Carolina, the number of wild mushroom species is really astonishing: over 3,000 species appear between the coastal plain and the Appalachian Mountains in western North Carolina. Many of those wild mushrooms are choice edibles, highly medicinal, or both.

My (Very) Short List of North Carolina Edible Mushrooms

To illustrate my point, let me try a little exercise: I am going to take three minutes and list the common names of some of the great edible wild mushrooms in North Carolina without consulting any resource materials:

1. Hen of the woods
2. Chicken of the woods
3. Oyster mushrooms (several species)
4. Blonde morels (several species)
5. Black morels
6. Lion’s mane
7. Bear’s head
8. Indigo lactarius
9. Fish cap lactarius
10. Fairy ring mushrooms
11. Parasol mushrooms (several species)
12. Chanterelle mushrooms (several species)
13. Lobster mushrooms
14. Hedgehog mushrooms
15. Aborted Entoloma
16. Caesar’s Amanita
17. Black trumpets
18. Blewitts
19. Reishi
20. Turkey Tail
21. Berkeley’s polypore
22. Sheep’s head polypore
23. Beefsteak polypore
24. Honey mushrooms

…OK, you get the idea. There are lots and lots of good edible wild mushrooms in North Carolina, so many that listing them would be a fool’s errand within the context of this blog post (there are more than 200). Expand your mushroom hunting horizons, and that list grows exponentially. If you travel to California, the Rocky Mountains, or the Pacific Northwest, or other regions to hunt mushrooms, you will find some amazing, abundant, and very tasty wild mushrooms at certain times of year that cannot be found on the east coast.
The profound diversity of wild mushrooms can be daunting, and there are different schools of thought about how best to organize and transmit mushroom-related information to would-be mycophiles.

To Lump or to Split, That is the Question…

Early on in my mushroom hunting endeavors, I visited an identification table at a foray and came across two gentlemen locked

in heated debate, nostrils flaring. One of them held a small pile of weensy, indistinct LBMs (little brown mushrooms) in his hand and was gesturing emphatically with the other toward another pile of small brown wild mushrooms already on the table. The other was glowering and shaking his head, a paper plate and a sharpie clutched in either hand, determined to put these new specimens into a separate species pile as opposed to adding them to the already identified mushrooms. Being a newbie and terrified of taxonomy (and thus anyone with experience in that arcane field), I steered clear of the scene and made a mental note to come back later and see what became of that questionable handful of specimens, to find out the end result of this conversation…Were these mushrooms the same as the ones already labeled and neatly arranged on the table, or were they a different species entirely? (in the end, they determined that they were two different species of Collybia).
This was the first time I saw an encounter between a lumper and a splitter. Allow me to explain.
Lumpers tend to clump mushrooms together into species and genera with plenty of regional variations, based on observations of mushrooms in different habitats. Despite variation, however, the lumpers tend to believe there are fewer distinct species of mushroom than their counterparts, the splitters.
Splitters, by contrast, cleave to a philosophy that most species have distinct genetic roots based on regional growth patterns and molecular phylogenetic markers, and thus things that look and act alike in different habitats are quite often different species. Genetic mapping frequently proves the splitters correct, but that doesn’t help much when one’s committed to learning mushrooms and isn’t blessed with access to gene-sequencing facilities, an eidetic memory, and an endless supply of time with which to read Mycotaxon and other academic journals dedicated to mushroom identification and mycology.

The Lumpers and Splitters Diverge on Amanita vernicocorra

To illustrate the difference between lumpers and splitters, a few years ago there was a rather fierce conflict (by mycological community standards) about one of the spring Amanitas, Amanita vernicocorra.  Amanita vernicocorra  is a lovely yellow-capped, edible springtime Amanita mushroom that occurs in Northern California from March through June in association with live oak, blue oak, black oak, and possibly manzanita, coastal madrone, and tanoak. There is a similar-looking mushroom that appears in the Pacific Northwest that grows in association with conifers.
The lumpers maintained that these two mushrooms were the same species. One of the splitters I know, a fellow named Dimitar Bojantchev, co-authored a paper demonstrating that, in fact, Amanita vernicocorra is exclusively a Northern California species, which means that the Pacific Northwest species is something entirely different. This turn of events in fungal phylogenetics and wild mushroom identification caused much gnashing of teeth and rending of hair among mushroom hunters who were used to calling their beloved Pacific Northwest mushroom Amanita vernicocorra. 
In the grand scheme of things, I don’t think either school of thought is “right” with a capital R, because it really depends on your personal wild mushroom hunting goals and the scope of your mycological ambitions. Lumping is helpful when one’s trying to learn a few mushrooms and gain a generalized understanding of wild fungi, as well as encouraging people to learn the gestalt of mushroom genera that look basically alike. For instance, I do not know all my Amanitas, but I do know an Amanita when I see one, because I recognize the common physical characteristics that species of this genus share. On the other hand, splitters give the field of mycology a rigor that keeps scientific inquiry running full speed, making mycology one of the most progressive, quickly evolving fields in the natural sciences. This is why I value both the lumpers and splitters, because each of them sheds light on different aspects of mushrooms that enrich me.
Like any living paradox, mushrooms buck binary 0-1 yes-no thinking, and so taking into account phylogenetics, folk knowledge/tradition, and observational data are, in a way, equally important to me. Wild mushrooms seem have a sense of humor about silly dualistic thinking, and so it behooves me to gather information from all corners of the mycophile community when I am trying to learn new things.

My Bottom Line: You Don’t Know Until You Go!

I’ve been both humbled and empowered by my work towards knowing the names of fungi — humbled by the impossibility of the task, and empowered because I continue to care and try my best. I don’t spend each waking moment studying photos of wild mushrooms and poring over dichotomous keys, but I do care enough to know that you don’t know until you go.
What I mean by that can easily be explained by an example — when one studies mushrooms (or anything else) the gestalt of an organism becomes familiar once you go forth and form a relationship with it. The example that is easiest for me to use is the difference between boletes and polypores — the differences between them may seem rather trivial to someone who’s never hunted mushrooms with porous underbellies, and thus it takes a good bit of verbiage to get someone who’s never looked for either to understand the difference between the two, and even then it might not stick unless they go mushroom hunting and find a few of each…and then the difference is as clear as the difference between blackberry jam and James Bond.

Learning to identify mushrooms, simply put, is just a matter of forming friendly relationships with mushrooms based on positive and memorable interactions with them. As you gain experience and see the same species time and time again, it becomes familiar to you, much in the same way that you can recognize your human friends. One of my mycophile buddies, a very strange and delightful person named Alan Rockefeller, had a pretty good way of putting it when I asked him to explain his philosophy on wild mushroom identification at a foray some time ago:

Maybe half of them have names…and the other half…DON’T actually have names…but when you see a mushroom, it basically screams out its identity to you, and you just have to look at it and pick up on what it’s saying. But, you know, most people look at a mushroom and they have no idea what it’s saying. See, like this one…it has a really slimy stem and it’s staining black, and there’s only one like that, and that’s Hygrocybe singerii.

Pictures help, of course, but even species-type collection photos can be pretty obscure without knowledge of what one is looking at, what features are the important ones in mushroom identification. Written descriptions in guidebooks shed light on what to look for, but field observations of a species give one a chance to learn in a way that is simply not possible with simple book study. For instance, your book might say something like “The cap of Gomphidius glutinosus, AKA the hideous gomphidius, is slimy,” but until you have handled a hideous gomphidius and it’s ogre-snot-textured cap, you might not remember this feature…but once you have, it will be indelibly imprinted on your memory.
When I think of those two dudes with their little brown mushrooms at the foray identification table, I am reminded that I will never know all the wild mushrooms. This does not disappoint me – it’s just more evidence of the fantastic diversity of Kingdom Fungi. And a motive to get out into the world and educate myself.
At the end of the day, fungi are mutualistically tied to their habitats in profound, complex ways. One mycorrhizal mushroom can be partnered with multiple trees, and is in constant interaction with the rest of its environment. The microbial population, soil chemistry, water resources, and climate all affect the mushroom’s behavior. Rather than steadfastly attempting to lump or split wild mushrooms into species, I love to step back and look at them from this behavioral standpoint as well, so I can better understand what they are doing in relation to the entire ecosystem, rather than simply trying to learn all their names (and then promptly forgetting them again). Finding a mushroom in the forest or meadow is an opportunity, an introduction, a mucho gusto from nature. If one is truly present, observant, and pleased by the interaction, the humble mushroom can reveal some interesting truths.