Burdock grows plentiful in fields in both CT and MI I am sure other places too, but this is where I know it.  For years I used be annoyed at the plant because little spurs would cling to you.  I was truly surprised to see the root was similar to a carrot, though much smaller and not orange of course.  I don't remember why I took it at the time but I remember him making a tea from it.

PLANTAINS!!!  This blows my mind.  I had a friend from Puerto Rico that told me a healer /shaman he knew there told him that any illness you have the earth provides the cure within walking distance of where you live ( I just assume he meant if you lived in the country).  But he pointed out plantains to me and I too always thought of them as weeds.  It's a shame how much we have  destroyed in the quest for the manicured lawn ...