WOW!
Interesting story about datura....
A couple of years ago I was at a friend's house and noticed a HUGE datura out front. I also noticed the seemingly glowing flowers. Suddenly this huge thing flew out of one of the flowers and into another one. It was dark, but I honestly thought it was a bat. I quickly folded the blossom closed and opened it under the porchlight to reveal a HUGE moth-like creature. It was a hummingbird moth:
And I think the flowers glow because of the UV light that is a natural part of sunlight. It's more noticeable at dusk and dawn. Apparently a lot of flowers glow under UV light...and this helps their pollinator insects fond them.
Here's an example:
http://www.naturfotograf.com/UV_GLEC_HED.html