I think on balance, taking into account flower colour and leaf shape, I would go with Brunfelsia pauciflora. It has an AGM, which makes a plant more widely grown due to it's many qualities. I have checked leaf shapes, along with flower descriptions of others and this seems to match best.
B. pauciflora is a spreading, bushy evergreen shrub to 3m in height, with glossy ovate leaves and terminal clusters of flowers 4-5cm across, opening purple and fading to near white.
http://apps.rhs.org.uk/plantse...
On the following site, the flower description matches well..
purple white eye ringed blue
http://www.erowid.org/plants/d...
That's about the best I can suggest, but it's not certain.
