Note: this is not a guide to surviving. This is probability. Statistics is king. You find a gray mushroom and eat it. If it turns out 99% of gray mushrooms in that area are poisonous, your chances at living are pretty low.
Welcome to the Man vs Stats!
Survival Situation Eating
People are living things. Eating is one of those things you can’t live without. So your boat or plane goes down in the middle of nowhere, and by some luck you’ve managed to make it to an island. Rumbling signals to you your stomach is empty. Right. Let’s find some chow!
There are a lot of fungi in the world. Conservative estimates say around a third to a fifth of fleshy fungal species are known. Nonetheless, mushrooms have an interesting situation. Some you can eat. Others you can eat but will induce powerful hallucinations. There are some so hard you’d break your teeth trying to bite them. Of course, some will outright kill.
That’s all fine and dandy, but what are the numbers? Around 50% of mushrooms are unpalatable. These include mushrooms too tough to eat (without processing) like Trametes versicolor or indigestible mushrooms.
What about generalizations based on color? Well sure, most people with a basic understanding of evolutionary biology realize species might take on vibrant colors (poisonous frogs!). But in a survival situation, non-mushroom-experts are going to have a hard time distinguishing round, fairly small, white mushrooms.
Case in point: below is Lycoperdon pyriforme, aka the Puffball mushroom. Go ahead and eat these.
This is the European Panther. Do not eat it.
More stats–an estimated 20% of mushrooms will be unpleasant to eat, whether psychoactive or causing digestive issues. 4% are fine and great to eat. See Agaricus biporus, aka the Portobello mushroom.
Looking disturbingly alike are the Amanita genus of mushrooms. Amanita bisporigera and Amanita phalloides account for most mushroom kills, and earn the names “Destroying Angel” and “Death Cap” respectively. Yeah. I’d stay away from these.
Mushrooms aren’t looking like a great bet. Based on the very very very limited data we have of all the mushroom species out their and their relative abundance, more than half are unpalatable. If you bite into one of these, you can always stop eating and look for softer fungi.
Some estimates say only 1% of mushrooms produce secondary metabolites deadly to humans. That’s actually not bad. It’s important to note that these don’t include the mushrooms that’ll make you have explosive diarrhea or terrifying hallucinations. But if survival is your primary initiative, then I think mushrooms are a pretty good bet, if you don’t mind getting a little uncomfortable.
Next up: Fruit, Fish, and Hunting!
Zeitlmayr L (1976). Wild Mushrooms:An Illustrated Handbook. Garden City Press, Hertfordshire. pp. 82–83. Ramsbottom J. (1954). Mushrooms & Toadstools: a study of the activities of fungi. London: Collins.