Here's one I have no idea about!
Small, chocolate brown all over, found on unimproved grassland.
If you know what it is, please let me know!
They are common throughout Britain and Ireland, they are saprobic, meaning they grow on dead wood, fallen branches of deciduous trees, most commonly beech. They can vary in size from 2 to 8 cm across the cap, and the crinkled nature of this one is not strictly typical. They are tough and rubbery and although not poisonous, are considered inedible.