Does anyone know what this plant is? [25KB picture at URL below]

It is growing in shallow water (about 5cm) at the edge of my pond, but
I also found one thriving on land some 20 metres away. As you can see
it has long green leaves with red veins, and a brittle stalk. In all
it is about 30cm high (above the waterline). I quite like it, but in
the long term am trying to grow native species, so was wondering what
is is and where it is from.

The picture is at:

http://www.unitedsystems.demon.co.uk/plant.jpg


J. Rickard