Mushrooms on a rotting tree stump in a lawn

Hundreds of mushrooms are rotting down the wood on this lawn. These are the fruiting bodies of the organism which is decomposing the old wood in the soil. Find out more about why mushrooms might be in your lawn.
Find out more about mushrooms on your lawn from these blog pages:

1. Question: Mushrooms on my lawn?
2. Why do I have mushrooms growing on my lawn?