I honestly don't know much about this one other that it is a volunteer in a lotus pond of all places, a result no doubt of my soil recycling program.<g>
I think Eatern Moon mostly because of the resemblance in the flower shape and it was in a neighboring pond while I had custody of it. The pads do go with the lily, but it is not a vivip and I think it is small mostly because it is in about 4" of water on a good day.<g>
When I get caught up, I plan to pull it and pamper it a bit then check for seed and viable pollen. I suspect it will get to be at least a medium. I haven't even looked for a tuber yet.<g> But it is lotus season and it is sitting in the midst of my Momo Botan, so it can't stay there for long.<g>