Giant Puffball

2016 October 1

On August 27, 2016, Sandy came back from a walk down the hill, and told us that she’d found a ripe giant puffball in the woods. So, the girls and I went down and retrieved it. Here it is:


This is basically a giant spore-bag. The interior is just a massive ball of dust.


So, what does one do with a ripe giant puffball? Kick it around!

The quantity of spores is incredible. That cloud of dust is billions and billions of tiny little spores, any one of which could potentially start a new fungus[1].


After kicking it around for a while, the remaining dedusted matrix looks a lot like a chunk of fiberglass insulation, and weighs practically nothing.


After dealing with this one, I remembered that there are sometimes giant puffballs right near our house, under a stand of mixed cedar, spruce, and virginia creeper. So I went poking around for a look, and sure enough, there was another ripe one, even bigger than the first:


There was also a somewhat smaller one that was not yet ripe (I think the other puffballs were actually from last year, and this one was the new growth for this year). It was about the size of a person’s head, and the color of a bleached skull:

“Alas! Poor Yorick!”

Giant puffballs, Calvatia gigantea, are widespread and found in moist, temperate woodlands all around the world. This is an unusually big fungus for this region. They are easily distinguishable from other mushrooms by their lack of a stem or any obvious internal structure. It supposedly has antibacterial activity and was formerly used as a wound dressing.

The thing is, both regular and giant puffballs are supposed to be edible if you get them before they go all to spores, and they are one of the few types of fungus where you can be reasonably certain that what you have is not some toxic lookalike. So I decided to try some. The unripe puffball sliced up nice, with a uniform, dense texture.


It didn’t look like it had converted to inedible spores yet,


and pieces of it tasted about like you’d expect a mushroom to taste, so I fried up some slices with butter. After cooking, it had a texture similar to tofu.

It tasted OK, but nothing really special. It was basically just fried mushroom. I ate several slices of it, and it seemed OK. But, in retrospect, I probably ate too much. For the next couple of days I felt a bit queasy and almost completely lost my appetite, to the point where I lost several pounds. Sam ate a fair amount too, but later that night didn’t feel well and ended up throwing up (after which she was OK again). Nobody else ate more than a small bit, and they felt fine. So, all in all, I don’t think we will try eating them again, or if we do it will only be in very small servings. It wasn’t like it was toxic, more like it was indigestible and just sat in the stomach taking up space[2].

Which goes to show that sometimes there is a difference between “edible” and “good to eat in large quantity”.

[1] Giant puffballs are what ecologists sometimes call “r” strategists – it is all about the quantity of offspring, not the quality. The fungus invests almost no effort into each individual spore, and a spore has so little in the way of reserves that it can only grow if it happens to land in perfectly ideal circumstances. The puffball doesn’t even put any effort into dispersing the spores, depending on falling raindrop splashes and animals tripping over (or kicking) the thing to get the spores airborne. But, the fungus produces so very very many spores (on the order of a trillion in a single puffball!) that even if only one in a billion is successful, the fungus will reproduce itself a thousand times over. This is completely opposite to humans, who have gone to the opposite extreme as “K” strategists, pouring effort and resources into our offspring for longer than most other animals even live. But as a direct result, when we have a child, that child’s likelihood of growing up is extremely high. We have virtually nothing in common with puffballs.

[2] Fungi resemble plants in that their cells have a rigid cell wall, but unlike plants they don’t use cellulose for the stiffening agent. Instead they use chitin, the same compound that arthropods use to stiffen their exoskeletons. I kind of suspect that the chitin is so indigestible that it took forever to pass through my digestive tract, and the fact that it wasn’t cellulose meant that my body didn’t really know what to do with it.

7 Responses
  1. Carole permalink
    October 1, 2016

    Very interesting, haven’t seen any nearly as large.

  2. Kevin permalink
    October 4, 2016

    Is kicking them around and breathing in the spores really the best idea? Lungs are warm, moist, and dark. Seems like a pretty good location to grow a spore.

    That said, we might sell them as a diet food.

  3. October 4, 2016

    While I wouldn’t recommend *trying* to inhale the spores, at 3-5 micrometers they are a bit larger than the 2.5 micrometers that is usually considered to be hazardous respirable dust (and unlike most dusts, spores are nearly monosized and so there isn’t a continuous range of progressively finer particles). And I’m not seeing anything in the literature about any of the kinds of mushrooms that grow in the ground successfully colonizing a person’s lungs. There are pathogenic fungi, but I think they are specialized to grow in living creatures and won’t just sprout up in the yard. I expect we are all OK.

    I agree that they probably would work as a diet food for the kind of person who is fond of crash diets, although afterwards I expect the person to be ravenously hungry and gain the weight back with a vengeance.

  4. October 4, 2016

    Chitin instead of cellulose? Fascinating! Also, it was great to hear the laughter of your kids. It made me smile. Thanks for sharing!

  5. Anne Bingham permalink
    October 5, 2016

    Thank you! I miss my puffballs — this is the first year since 2012 that we haven’t had any in a wooded area at the back of the house. It’s probably my fault for trying to preserve them instead of kicking them around to disperse the spores, although an unusually damp summer might be a contributing factor.

  6. Mark Sturtevant permalink
    October 7, 2016

    Really interesting. I have never seen one that big.

  7. Ace permalink
    October 10, 2021

    From Wikipedia

    “Lycoperdonosis is a respiratory disease caused by the inhalation of large amounts of spores from mature puffballs. It is classified as a hypersensitivity pneumonitis (also called extrinsic allergic alveolitis)—an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled natural dusts.”

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