Blue flower I should like to identify

• 23 Aug, 2012
• 3 likes

The flowers are on a plant that is growing ever taller, actually leaning on our runner beans!. They open from the pods you can see and later the pods close for the seed head to form. The flowers open in the day - not sure if it is only for one day at a time. I was given one a few years ago and I think this one must have emerged from seed that got onto the compost heap.