"Corn" is not a species.
Nobel Prize Laureate George Beadle convincingly showed that teosinte was the ancestor of Zea mays. i.e. speciation, by all scientific criteria. (Sorry, George, where ever you are in the Great Beyond to have sullied your name with Havoc. Please don't haunt me).
Corn is corn, bub. If you want to play semantics games, that's your problem - normal human beings know what corn is even if you don't.