There are upto 70 different species of water lilies. These are grouped into: night, tropical and hardy ones. Night lilies bloom in the night. Tropical lilies can be found in tropical climates and bloom at all times of the day. Hardy lilies are able to withstand most conditions and are the most common, like the one here in my pond.

The water lily has long, stout leaves and long flower stalks. There are usually six petals and six stamen. Water lilies are also able to reproduce by budding. The roots detach and grow into new water lilies. The root of the lily is located at the bottom of a pond.

Most species of lilies grow rapidly and need repotting every couple of years, you will see that the roots will start to split the pot that you have it in, When you remove the plant from its pot, rinse the root with water from the garden hose. You will see along the rhizome "crowns" where groups of new lily pads emerge.
Using a sharp knife, slice between these crowns and each section can become a new plant.
Within a few years you could have yourself a pond full of Colourful lilies