HC Cuba as it is popularly known is one of the smallest aquarium plants in the world. This is a fairly recent addition to the list of plants used in aquariums and has proven to be very popular.
It could be planted in small clumps, a few centimeters apart. It is usually sold in its emersed state so it will need weighing down to prevent it from floating to the water surface. The roots being very small make it difficult to anchor to the substrate. Ideally use powder soil for the success of the plant.