Have you ever thought about using European Frogbit (Hydrocharis morsus-ranae)? Its an invasive but one of the places that I go dip netting has it in abundance so I get some when I go out there. It does really well in most of my aquariums.
I like the look of lillie pads and plants with round platform style leaves, but I would just get some pennywort for that
long story short I have a friend who collects natives and ended up with a lilly bulb from him... it will put off tiny pads but doesn't do much. not sure what species it is but I'm pretty sure it's a native. it's neither thriving or dying. But my fish leave it alone for the most part.