These look like brown puffballs, but they have a broad stalk and the surface is covered by tiny brown warty things.

The white mass inside (visible because something has been nibbling these) develops into spores. These get dispersed through an opening that forms at the top. Rain drops hitting the puff ball cause a puffing action.

The second photo shows the remnants of a large group of L. perlatum, quite clearly showing the opening in each puffball through which the spores are puffed.