Ludwigia And Rotala.

[JamesC]

14gtr14 hit the nail on the head. The older growth is emersed growth and what you are seeing now is submerged growth. Let it grow above the water line and it will start growing the round redder leaves again. It can be quite good fun growing plants out of the water. A lot of aquarium plants are grown emersed and look very different when grown submerged.

James