This was blooming in a hobbyist pond this summer and looked quite beautiful. Due to the dry conditions it was hard to keep up with topping the ponds off at work. We didn't grow anything like this flower either. The 70 different species of Nymphaea fall into two categories hardy or tropical. The hardy types are diurnal blooming with the tropical types blooming during the day and night.
Since it is Sunday here is the bonus snapshot.
Synonym: Begonia evansiana
This plant has always interested me but I have never had the guts to try it. Perhaps Long Island, with their slightly less harsh winter will be a good trial for it. If can colonize some shade areas that would be great.