Most fleshy mushrooms tend to arise from the forest floor.
It is actually a very poisonous Amanita button that when very young that just looks puffball-y. Also, not all Puffballs look quite LIKE Puffballs. These are probably stalked puffballs of the order Tulostomatales, where the puffball seems to 'sit' on a material different from the ball itself. Pretty alien when you look at these things with a magnifying lens, but they are fairly common in these woods. A great general mushroom site is Tom Volk's Mushroom Page, and is in association with the University of Wisconsin at LaCrosse.