Thanks!

Iris versicolor (Harlequin Blue Flag)
Iris virginica (Virginia Iris)
Iris fulva (Copper Iris)
Iris pseudacorus (Pale Yellow Iris) Introduced, but a widespread species.
Orontium aquaticum (Golden Club)
Sagittaria sp. (Arrowhead)
Peltandra virginica (Green Arrow Arum)
Nymphaea odorata (American white waterlily)
Rb

Razorback,
That's a great list...and I have most of them as marginals and the water lily. I love them all.

I did find that Hornwort or coontail (Ceratophyllum demersum)is a native floating plant and can usually be purchased. Water buttercup (Ranunculus aquatilis)is another native, but nearly impossible to buy.

I also got some great suggestions from the aquatic plant guy at the IN DNR. Just pasting his email below:

"For floating plants the best options would be spatterdock (Nuphar advena) (actually kind of emergent since the leaves don't float on the water's surface), white water lily (Nymphaea odorata), and watershield (Brasenia schreberi). Spatterdock and water lily can sometimes densely ring a pond although spatterdock has the greater tendency. Watershield is a cute little plant, but you generally only see it in the SE part of the state, I also don't think it is much used in trade. Most of the water lilies for sale are non-native species. Most of the spatterdock for sale is probably Nuphar lutea, a Eurasian species.
Most people do not look to plant submersed species since they are usually already present in most lakes and they usually show up pretty quickly after a pond is built. People typically are more interested in killing the submersed species than they are planting them. It are the water garden types of folks that get told that for their water gardens they need to put in an "oxygenator" plant. They then think that ponds need these same things. Probably the most common native submersed species in trade are coontail or hornwort (Ceratophyllum demersum) and native elodea (Elodea canadensis). Coontail can definitely become a major nuisance and sometimes elodea can as well. My main tip for those thinking they need to add submersed species is to wait. If conditions are suitable for submersed plant growth the plants will show up soon. If conditions are not good (turbid water, little shallow water, poor substrate), no matter how much planting, one will probably not get much growth. Unfortunately, invasive species tend to do well in the conditions that do not favor our natives."