[HeyPK]

I had a cattail seed germinate in one of my tanks, and it grew rapidly as a totally submersed plant until it got big enough to poke through the surface. It should be possible to keep the plant from becoming emersed by trimming the larger leaves and keeping it small in the same way that one keeps Nymphaea species from producing floating leaves.

Other plants that poke up through the surface would include the thick stemmed Hygrophila species, such as H. corymbosa.