Hi Sandra,
I was just reading your 'Ask a Question' thread about shade cloth and saw where
@OldGardener had mentioned my name and here you are!
The flower you are referring to is the Moonflower as it opens. Moonflowers open in stages starting in late afternoon so that they are in full bloom about the same time it's dark. This image was probably taken just before sunset as the bloom unfurled.
Is this the one you meant?
Happy Gardening!
