Wow! I just learned that corn is NOT a naturally occurring plant! What we know as corn is a completely man-manipulated plant that originated in central Mexico as a grass that grew just a few kernels in each sparsely-distributed plant.

Also, NO corn on the entire planet can grow without human intervention and tending. Every plant has to begin with a fresh seed and if we stopped planting corn seeds today, the entire world would be without corn inside of 3 years.

This paraphrase courtesy of Modern Marvels: Corn
The History Channel