This one was about a handspan (25cm) across. They can get very much larger.
They always grow on the soil, never on rotten wood. I have found them in fields where sheep or cattle have grazed.
Olympus EM-1, (aperture priority), Olympus m4/3 30mm f3.5 ED macro, 1/80 at f10 ISO 1250, hand-held.
The stereos are crosseye and conventional.