They are puffballs! As a kid I think we all have done this at one point. You see a small white ball in the yard and run up to it, the leg pulls back and then swings forward, expecting to see a golf ball roll across the yard at amazing speeds and instead a huge dark cloud erupts causing you to run away and leaving your shoes distinctively dirty. You have just liberated thousands of fungal spores into the atmosphere.
The culprit is a puffball, a type of fungi in the same group (Basidiomycetes) as the normal mushrooms we are used to. This family of that group (Lycoperdaceae) instead forms a ball-shaped fruiting body that’s filled with spores at maturity. There are a few different species of puffballs in the Northeastern U.S. and even a few of those are edible. The trick is to gather them when the time is right and as with most fungi, that’s early.
There are pictures online of the giant puffball (Calvatia gigantea) which grows as big as a Thanksgiving Turkey. The species I found growing at work the other day however is Calvatia cyathiformis, the purple-spored puffball. When fresh the flesh of the mushroom is a nice clean white color and as they age, the flesh matures into spores that are purple-ish in color.
So, I mentioned eating puffballs and I guess I should comment specifically on this species. It is in fact edible and if you want to try eating some wild fungi this is a group that is fairly easy to identify. (insert my usual legal disclaimer about eating fungi- aka. dont if you dont know what you are doing). So here are the steps, 1. identify the mushroom, 2. make sure it’s still young and fresh, 3. cut open each one to verify it isn’t an ‘egg’ of the deadly Amanita genus, and 4. cook thoroughly.