Plant ID Help Please
I'm not sure what the plant pictured below is. The first photo shows the stem structure, and the second attempts to show the types of leaves at the top. They're different from the leaves along the stem, most of which grew in my tank, although it may have originally started off emersed.
There are no branches, just one solid stalk which has gotten thicker over time. The plant has just put out three tendrils (roots?) from the stalk that can be seen in one of the photos. I'd like to propagate, but I don't really know how to without knowing more about the plant. It's the only one in my tank, and so some ID advice would be great so I can better prune it and hopefully propagate.
Edit: I realized you can't see from the photos, but the stem is... segmented? Almost like bamboo... there's two leaves (opposite sides) per segment, until it gets to that really leafy crown.