Ceratopteris pteroides is popularly known as floating fern, and comes from South America. It is one of the largest floating plants.
The thick mat provided by the immersed roots is ideal for some species to spawn. Siamese fighters, for instance, like to spawn under the leaves. It also offers a haven for young livebearers.
The pretty rosette-shaped plant can grow to a big diameter under favourable conditions, and is generally seen covered with a mass of young plants which form on the larger parent plant leaves.
As it demands a humid atmosphere, it grows much better in a covered aquarium, where no direct rays from the lights can dry or scorch it.
It is a great idea to remove any snails from a tank containing this plant; they are rather inclined to make a meal of it.