I think this is just regular C. undulata. The color of the leaves can vary depending on emersed vs. immersed growth, lighting levels, and other growing conditions. I have a ton of these, so while I didn't take a super long look at your pictures, I can assure you that it is highly likely these are indeed C. undulata. If you'd be interested in doing some sort of trade, perhaps I could compare it to my C. undulata, (I have oodles of them!), what conditions do you keep these in?