Thanks to Everyone who has posted thus far. Ludwigia feels right, but the root mass & structure and the fully emersed nature of the plant suggested otherwise. I will go take some proper photos of the same plant in natural sunlight where I collected it and post for your opinions.
There are some other very cool plants out in the pond. Some 2"-3" lily pads and some fully submersed grass-like plant. I need to get some more aquariums running.