From the Amazon

I visited the Adelaide Botanic Garden today, and called into the Amazon Waterlily Pavilion. I was lucky to see the Victoria amazonica in flower. One writer explains that the plant flowers only occasionally and very briefly: 

Only blooming for a few days, the flowers will open at nighttime on the first day being white.  When they open on the second night, they will be purple-red color and will have lost their scent.

The website of the Adelaide Botanic Gardens has more information.