Nut Tree/Shrub Identification

Hello,

I was recently walking my property in central Minnesota (zone 3b) and found a small tree/shrub with what appear to be nuts on it.
My first thought was "wild hazelnut", but the leaves do not look like hazelnut- more like oak?

Is it possible that what appear to be nuts are actually some type of insect cocoons or disease on the tree?

Any suggestions on what it might be?

Thanks,

Andre

Hi Andre, I am going to say that those are insects. Do you see the holes in the "nuts" ? That is where the insect emerges. I have them all over my aspen trees. This is where they live through the winter. I believe they are a beneficial wasp.

Gall wasp

definitely Gall wasps very common here in France