Poisonous: Though not life-threatening, if consumed the Earth Ball will cause gastric upset.
I hate Earth Balls. It pains me to dignify them with a capital letter, and I only do so for consistency. They are the warts of the forest floor, and you will find them everywhere. They are extremely persistent little growths, and I wouldn’t be surprised if they stubbornly endured to feed the cockroaches if that nuclear disaster were ever to strike.
They do an important job, of course, as all mushrooms do: digesting the leaf litter and replenishing the soil with the vital nutrients it needs to feed the other plant life. But I don’t care. They are just too many.
I am joking, of course… well, slightly. Earth Balls have the infuriating habit of appearing in the corner of your eye when nothing much else in the way of mushrooms are about. Many a time have I returned home from a fungal foray with nothing to show for my efforts but an empty basket, deflated all the more by the masses of Earth Balls that have given me a false flash of excitement in my periphery vision. I swear these things are just put there to torment me.
The Earth Ball pictured here and on my Puffball post is a Common Earth Ball. You shouldn’t really confuse Puffballs with Earth Balls, but if you are unsure, just give whatever you have a firm squeeze between your fingers: Puffballs will squish and squidge like a marshmallow, whereas Earth Balls will be more resistant to the pressure, and the thick skin will crack and split rather like that of an under-ripe Passion Fruit. Another difference is that the inner flesh of Earth Balls is never pure white, like Puffballs are when in perfect condition for eating.
For further pictures and description, see my Poisonous Mushrooms A-Z page.