This is a chestnut tree (Castanea dentata). It’s in Stewart’ s Woods, aka Hort Park woods on the west side of Purdue campus. Quite possibly the last native chestnut still growing in the county. Before the chestnut blight (Cryphonectria parasitica) hit the continent about a hundred years ago, this was a common tree in Indiana and reached great size. The roots of this particular tree could be the survivor of such a great trunk that died from the blight, as typically the roots of a blighted tree live on. The first picture shows the current medium size trunk with saplings sprouting up from the same roots. I had heard that this tree was out here but I never could find it until now. I saw the burrs on the ground (in the last picture) first, which clued me in that there was a chestnut tree close, then I looked up and saw the tree standing there in front of me.