Texas Grey,
I'm not an expert on aquatic plants in any way, but it looks similar to the type of water primrose we have at our place. Is it flowering at all?
Here is a link to a picture of what is supposedly water primrose, and it looks very similar to what you have.
http://www.arc.govt.nz/arc/fms/Plant%20me%20instead/Ludwigiaperuviana.gif The picture is not very big, but hopefully it will still help. I know water primrose can look different in different areas. If it is indeed primrose, know that it can be very invasive. I recall reading threads on here that discuss it extensively. We're letting our primrose grow for now, since our fish need the cover, but it is definitely something to watch closely.
Hopefully others who are more knowledgable can give some better advice.
