Corn is a large grain plant. Several other foods are made from corn such as popcorn and lollipops.
Captain Kyle Rogers and SG-X were taught that corn and cotton were indigenous to North America in order to infiltrate Stargate Command. (SG1: "Rules of Engagement")
Dr. Richard Flemming developed hybrid strains of disease resistant corn and cotton. (SG1: "Nightwalkers")
The Lucian Alliance crop Kassa was very similar to corn. (SG1: "Off the Grid")