It looks like I. fulva. It could be an intentional hybrid or just a collected natural hybrid.
red I. fulva
It could also be I nelsonii. Both can be very red. Nelsonii has a much smaller natural habitat.
I. nelsonii formerly known as the Abbeville Reds
Telling the two apart is not an easy thing to do.
The Society for Louisiana Iris website has a commercial directory. You might start there.