Vallisneria americana (gigantea) is an easy plant that grows fast, suitable for large aquariums. In most aquariums the leaves grow so long that they float on the surface. So the plant needs pruning to stop it taking too much light from plants growing beneath. The leaves are tough and strong, so they are not normally eaten by herbivorous fish. Vallisneria americana is easy to propagate using runners, which are prolific if the bottom is nutritious.