Out for a nice fall walk at a nature preserve today and stumbled across these.  They were all oriented up the same way.  I first thought they were nuts with husks on them until I broke one open.  It is firm and whitish green inside.  The outside felt waxy and smelled like a pear.  I took another one home and cut it open.  I figure a type of mushroom or puffball.  It was near a mix of hardwoods.  What do you think?