I don't think that it's a rust... I think that it's a foilage disease which seem to be fairly common in aspens. The leaves have pale green spots....
Thanks! I was just trying to find some information on it, 'cause it looked kind of interesting... Anyways, thanks again!
I found it in Colorado... I tried to find what it was by myself. At first I thought it was some kind of nightshade, but it didn't look at all like...
