ludwigia proof

The plant itself is answering my question: ludwigia or hygro? The far right, smaller one in this picture is the same plant featured in this previous shot. Now that ferts have been adjusted (root tabs added again) it's finally growing more, and looks to be changing shape. Foliage is getting noticably longer, narrow and brighter green.

I absolutely know this was this stem of ludwigia repens that came out of my tenner months ago- it had the rounder leaf shape and darker olive green with purplish undersides. Well, I don't have to wait for chance flowers now to identify.