Do some flowers fluoresce? Some deep purple Lobelias and larkspurs seem to glow and confuse my eyes in sunlight. It reminds me of those blue LED Christmas lights (they come in strings with other colors) - the blue ones only seem to be showing two colors at once.
Many flowers fluoresce under the influence of UV and white light. The compounds that fluoresce are called Betalains, and are either red/purple (betacyanins) or yellow (betaxanthins).
It is thought that this is a method of making the flowers more obvious to insect pollinators. However, there is some debate about whether the fluorescence contributes to this much compared to just the bright colours.