I Found this on the Ground. What is it?
What is this? I found it this morning on the ground. There are no others on the ground like it nor that I can see in the trees above. However, there are very tall trees in this area so I can't see anything very closely.
This looks like a leaf gall (the leaf is still attached and looks like an immature oak leaf.) These are caused by tiny wasps laying their eggs in the leaf. The gall is actually the reaction of the leaf to the disturbance. Galls are almost all not harmful, and this is not one of the harmful ones.