We call it ditch weed in Iowa. Don't know if it is the same stuff you smoke but it looks like it. I think it is hemp. If hemp grows everywhere here would the stuff you smoke do well too? Here when you open ground no matter how small spot it is you might be sure there will be ditch weed growing shortly after. When I bought my property there was a feed lot on the back. Shortly after the renter removed the cows there was a forest of weed. I had no clue what it was until my neighbor told me. The plants were at least 6-10 ft tall and few inches thick. I tried to use Grasshopper mower to knock them down but it was impossible. Then at fall I tried to burn it but there was not enough fuel density to sustain the fire. My neighbors were joking that I wanted to get them all high. I gave up on getting rid of it. Year later the plants were only about 3-4 feet tall and every following year got smaller. I think about four years later there were only few scattered plants.
I did some reading about the hemp story in Iowa. Hemp used to be a crop during WW1.
Hemp A War Crop for Iowa – Global Hemp