No, it's some sort of carpet plant. Most true
carpet plants are pretty tricky. Dwarf hairgrass is probably the easiest carpet to do without CO2, you can always trim it to a smaller size. You can "cheat" a little and use moss as a carpet, or a plant called round pellia, if you weigh it down with plastic mesh over top (since it floats), it will eventually grow over. The pellia could look beautiful even in a very low-tech set up over time.
All of those lush, fluffy "fields" you see are made possible with CO2 injection and high light. This keeps the plants low to the ground as there's no "need" for them to reach up, and lets them spread out more over the substrate.