I recently took my dog for a walk and found a load of what I believe to be either japanese knotweed or black bindweed.
The flower was all wrong for j knotweed , but the flowers seemed similar to black bindweed BUT on all the photos I have seen on the net, there is nowhere near as much profusion as I have seen
I took a photo but then I deleted it by accident, thinking it was just another garden escapee.

Is there a garden species of black bindweed? or similar?