Traditionally, on the Lake Ponchartrain Northshore (before nature-hating types who should have stayed in New Orleans started ruining the place), the ditches were planted in Canna Lilies (there are native/wild cultivars)and Elephant Ears (again, I think there were native types).

Louisiana Iris, I've seen a lot around Ponchatoula. The common yellow variety seems to grow like Topsy in ditches.

And there are native bulbs, like Swamp Hymenocallis, which thrive in boggy conditions. You do realize that some Bamboo is non-invasive, right? It's grouped as 'clumping Bamboo'.

Rosa Palustris (swamp rose) tolerates wet feet, and is a real beauty (native to your area, too).

There's an 'Invasive Exotic' I've noticed in South Louisiana ditches (which adds much beauty to the landscape, with its Vermillion blossoms). Can't remember the name, and my browser is so 'improved', now, it's jumping around too much, and won't take me where I want to go (used to be easy to look it up). Anyway, it's in the Locust family, and is a small tree with fern-like leaves.

AFAIK, there are no types of Elephant Ears native to Louisiana or the U.S., if you're referring to the Colocasia/Alocasia seen growing in ditches everywhere. There is also no native Caladium, according to USDA Plants.

That "common yellow variety" of iris growing in ditches is Iris pseudacorus, and it is a foreign invasive. Please do not plant it.

Louisiana does have a lovely NATIVE bamboo, Arundinaria gigantea. It is not as difficult to control or remove as foreign bamboo if it overgrows its boundaries.

Highly recommend the Wildflower site for info about native substitutes for common non-native landscaping plants.

For other recommendations, google the phrase "native plant alternatives" and you will find a wealth of information.

Here is a link that might be useful: Native plants for Louisiana

Oh, I forgot to mention this one: This THRIVES with wet feet, and is perfect for a ditch in full sun:
Equisetum hyemale 'HorseTail' Rush. The Bamboo Plantation in Brookhaven, Mississippi carries it. But I'd imagine it's a popular item at plant swaps, too. My Grandmothers loved it for arrangements. If you're in a Modern/Midcentury house, you can make stylistically appropriate 'Oriental' arrangements using Horsetail Rush, straight out of the 1950s floral arrangement books.

I also forgot plain-ol' Swamp Palmetto, which is hideously expensive to buy (but you can plant the seeds...).

Banana trees do GREAT here providing sturdy soil along our ditches, as do the Elephant ears in shaded areas. The bamboo we have does an amazing job at preventing erosion but alas is so invasive itself, being in the grass family, it'll spread just like a lawn :-/