One of the most exciting aspects of mycology, the study of fungi, is the lack of answers we have to many of the very fundamental questions it poses. What’s so enticing about our collective fungal ignorance?
Even a citizen scientist working out of their spare bedroom has the potential to discover new species, relationships, and contribute to this burgeoning science.
One question we have no answer to, and probably never will, is how many fungal species and mushrooms populate planet earth?
Yet we can always try and guess, no? Right now, our best approximation pegs the number of species at between 2.2 million and 3.8 million species.
As proof of our mycological ignorance, consider this: of these millions of fungal species, only around 150,000 have been described.
As is the case with most life on earth, fungi are named and described using the general taxonomic classifications of, from least specific to most specific:
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
As an example, the common button mushroom found in grocery stores is, from kingdom down to species, classified as: Eukarya, Fungi, Basidiomycota, Agaricomycetes, Agaricales, Agaricaceae, Agaricus, Bisporus.
Given the lack of study, segments of the fungal kingdom are constantly being reclassified and shuffled about. As a result, the number of fungal phylum depends on whom you ask. In Radical Mycology, an exhaustive mycological tome published in 2016, author Peter McCoy pegs the number at seven — Chytridiomycota, Blastocladiomycota, Neocallismastigomycota, Microsoridiamycota, Glomeromycota, Ascomycota, and Basidiomycota. But others say it’s more like 10 or 11.
If this is getting a bit complicated and overwhelming, well, welcome to the world of mycology, where nothing is straightforward.
How about one more factoid to further demonstrate the mid-boggling diversity within the fungi kingdom?
It’s been discovered that some fungal species, like Schizophyllum commune (aka the split gill mushroom) have more than 20,000 different sexes.
An Important Distinction
In an effort to clear up a common misconception in the general public about fungi, let us be direct: fungi and mushrooms are not synonymous. More specifically, all mushrooms are fungi but not all fungi produce mushrooms.
Mushrooms are actually just the fruiting body of a specific fungus. The main purpose of the actual mushrooms is to spread fungal spores in an attempt to sexually reproduce with another species of the same fungi. Put another way, mushrooms are to fungi what sexual organs are to humans.
So, when mycologists estimate that there are between 2.2 million and 3.8 million species of fungi, that does not mean there are that many different mushrooms buried within and/or popping out of the ground.
To further narrow things down, researchers have identified around 2,100 edible species but only about 1% of those are actually cultivated, wild harvested, or colloquially known as “choice” or “gourmet” mushrooms for their revered flavor.
And while many believe the number of medicinal mushrooms may someday far exceed the number of edible mushrooms, the science is still quite young and only about 1,000 known macro-fungi (i.e. mushroom fruit bodies) with medicinal properties have been discovered to date.
So, next time you stumble upon a mushroom out in nature, perhaps it’s worth taking a photo. You may have just found a completely new species which means, hey hey, you could have the chance to name it after yourself, your Mom, your dog, whatever!
- Radical Mycology, Peter McCoy