greater bindweed (Convolvulus sepium)

I photographed this bindweed over back wall of one of the gardens surrounding the short stay car park on Mill Road, Cambridgem while waiting for Arco Iris Samba Band to start towards Harston and Newton Primary School Fête. While I was finding the best angle, a woman and her child arrived on their bikes and got through the back door of a garden. I turned and found her looking at me, smiling. We had a short chat, her saying that "it's so nice somebody notices how beautiful those white flowers are" and that "Ipomoea (the type of bindweed with large blue-purple flowers) is a weed in my country". Unfortunately, I didn't have time to establish what her country actually was, but the conversation made me remember that Ipomoea is also weed in Portugal, where we were on holidays last year. Porto, especially old town, seems to be pretty much covered in it in august.