Our lawn is over-shaded by a large spruce and the grass suffers. In Spring, beneath the branches, fungus appears in the lawn. It looks like half an egg shell, buried in the ground, with the open end pointing to the sky. The fungus disappears in a few weeks but we would like to know whether it's harmful. It's not something that we would like to retain and if there was a safe treatment to eradicate it, we would do so. Any ideas please?