I thought I knew all the plants that would attack me in southern Illinois…then I headed off trail to find a good spot for a cathole and started to push through a shoulder-high thicket of these guys:
This proved to be a mistake, due to the hitherto-unnoticed-by-me spiky thorns all over their stems. I found another spot, so now I’m just left with small punctures & curiosity.
I have not used LeafSnap (and probably should!). Maybe I’ll remember the next time I’m in that neck of the woods.
Don’t use an app. There are many flora and fauna books for Identifying you can get under $20. I should check mine for the Midwest.