[click on image to see a larger one]
Triptych of human vision, UV and simulated bee vision (left to right):

This Dandelion flower has quite a prominent UV pattern, its petals are UV bright around 365nm, its center is UV dark, especially the anthers, and this gets quite nicely visible, also in simulated bee vision.
I have written about this flower previously HERE
Stay tuned, more will follow on that fascinating subject...
More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos