There's definitely more going on with trees than we once thought, but I'm at least confident that wherever human consciousness comes from, it certainly must be tied to the nervous system. If we inherited consciousness from our ancestors, then the most distant common ancestor that we could possibly have inherited it from would be at most around the point where we branched from jellyfish. So if trees or other plants are conscious in their own way, then they also must have independently evolved it in their own way; it's not a trait that they share with us based on common heritage alone.