They look just like field corn stalks or sweet corn stalks. Usually popcorn is smaller stalks and ears. If you know what a corn stalk looks like it is a smaller version than what you see growing in fields.
Popcorn stalks are shorter and thinner than sweet corn stalks and much shorter and thinner than field corn stalks. Sweet corn being grown for human consumption and field corn being grown mainly for livestock consumption. I live in Iowa and know way too much about corn.