Mushrooms in Wood Chip Mulch
On the Michigan Tech campus, between the Chemical Sciences and Electrical Engineering buildings, there is a wooded patch with pine trees, that has been mulched with wood chips. And on June 20, 2025, I noticed that there was a substantial flush of mushrooms coming up right there.
There were quite a lot of them, emerging in dense clusters.
The newly-emerged caps looked like buttons, and could be mistaken for puffballs by someone who wasn’t looking too closely,
but once the fruiting bodies matured they were clearly a fairly classical mushroom shape.
Flipping one over, we see that the stem has the remains of the “veil”, a membrane that originally enclosed the head of the mushroom, and only remains as a thin tatter.
This is clearly one of the “gilled” mushrooms, with the spore-producing structures being thin parallel sheets.
From a combination of their appearance, and when/where they were growing, there is a good chance that these are Agrocybe_praecox, sometimes known as the Spring Fieldcap. They are a very common gilled mushroom (check) that is well known for growing in wood-chip mulch (check) and for emerging in the spring and early summer (check).
Mushrooms like this come up very fast, because they do most of their development underground before emerging. Once they pop up, they get to full size in just a few days. It is basically a combination of growing (due to increasing the number of cells) and inflating (due to being filled with fluid). These are just the visible part of the organism, most of the fungus is the mycelia, strands growing underground where they can extract food and energy by decomposition of organic matter. The mushrooms themselves are just spore-spreading devices.
There are a lot of mushrooms that look a lot like these. The family of mushrooms that they belong to has a lot of toxic members, including the really toxic ones like the “Destroying Angels”, so I wouldn’t recommend trying to eat these[1]. While the Wikipedia page says that this exact species isn’t generally regarded as toxic, it apparently tastes fairly nasty, and “it is of debatable culinary interest”.
[1] Eating wild mushrooms is a lot like playing Russian roulette. It has significant risk without any real noteworthy benefits, unless the risk is the primary reason why you are doing it. Even the most delicious mushrooms in the world aren’t all that great, and a lot of the wild ones taste kind of foul even if they don’t kill you outright. If all you want is dinner, you want cultivated mushrooms, not wild ones.