Very interesting... I just watched a documentary last week on Monsanto and their GMO corn.... apparently when gmo corn crosses with non-gmo corn the results can be mutated corn... and the result is what you have growing in your compost.... they referred to this as "trans-genic" corn.

I would pull it out and destroy it, as in burn it.

I am going to see how it turns out. I am growing it more for decoration than eating (though it can be used as popcorn). I am the only one in the area with any vegetable garden, and last year I had 3 varieties. Glass gem, which is an heirloom variety, purchased from Native Seeds - a nonprofit in Arizona, and 2 varieties I likely got from Burpee and could have come from Monsanto - strawberry corn and caramel-krisp corn. The 3 varieties had staggered maturities and I didn't have any cross-breeding problems last year, though this plant sprung from a discarded ear from then. These are the only two years I have grown corn, though, so I wanted to make sure this was something unusual and not something that happens and I just hadn't seen before. The picture doesn't show it, but this plant also towers over all my other ones, even others that sprouted in the compost (lesson to self, careful what I toss in there).

If anyone else has any thoughts on this, or has seen it before, would be glad to hear it. I will post an update once I see how it turns out.