Wanting to say Najas(Guppy grass) which if that is it, will grow to the top.
Has thin stems which I've heard called delicate before. Doesn't really seem that way
to me. Is hard to get rid of if left to cover any size aria because the roots seem to keep sending up new shoot even after I pull the plant out.
I like it though as it gives an aria of "jungle" but unless it got very dense you can see
through it to see your fish. I think it's an excelent plant for smaller tanks where big leaves would hide everything from view.
But I'm not able to more than guess as the picture is not that clear.
This is far from the best picture but gives a shot of a new plant of the kind I said. http://www.plantedtank.net/forums/picture.php?albumid=14281&pictureid=58858