Looks like there's one less species of iris in Louisiana than we thought. For most of modern time, the common blue iris of the south have been Iris hexagona and Iris virginica. But recent genetic studies revealed that I. hexagona are limited to a few small areas of South Carolina and Florida. The rest all seems to be Iris virginica var. shrevei, which you see here from Louisiana. One species has six sided ovaries and fruit, the other has three sides. It doesn't seem like it would be that hard to tell them apart. Is there more to the story?