Ultra Violet!
I'm not expert on flora, but I suspect this is a ceanothus with the most amazing tiny little flowers.
The back story is that I was photographing a group of young fundraisers with a massive cheque and we were waiting for a teacher to come along to complete the group for the shot.
I was standing next to this fabulous bush and it caught my eye. With a camera in hand, what's a bloke to do?. Original public domain image from Flickr