A puffball is a round fungus, often white or brown, that looks like a soft ball sitting on the ground. When it is ripe it bursts, or someone kicks it, and a cloud of dust flies out. That dust is spores — the fungus’s way of making more of itself. Learner books sometimes say “seeds,” which is the easy picture; though actually a fungus does not make seeds the way a plant does. It is not the usual mushroom with a clear cap and stem. Some kinds are eaten when they are still young and white inside; old dry ones are only dust. Do not eat a wild one unless you truly know it.

馬勃（會噴出孢子粉的圓形真菌）