I'll second the fact that they are not carpet plants.
Dry start method if you want to try to grow them, though. I used a small suction cup glass pot with some Fluval plant/shrimp soil. Kept it at a level in the tank where the water keeps the soil moist. Sprinkled the seeds on, kept the lights on the normal cycle, and they grew quite well. Took 4-7 days to germinate. Initially the seeds get wet and create a sort of gel layer around themselves that makes them very sticky.
At one point I posted the adult plant, submersed and emersed growth on a forum and got an ID. Can't remember what/where, though. Maybe it was a hygrophila species, polysperma or something...