I bought my fire bellied newt (Cynops orientalis) a water hyacinth.
These are commonly sold as pond plants, they float and look rather exotic, don't you think?
I've seen them in the wild in the Niger river, too.
The newt lives in a tank with a low water level, so plants that rise above the water surface work well there. I've found that she likes to sit or hang in the roots of the plant.