Wisteria

Wisteria a hardy climber.  Seen here in the pretty purple colour.  There are many varieties and I do not know which one this is.. possibly the Wisteria floribunda - the Japanese Wisteria. Family: Fabaceae (Pea family)

They are said to grow vigorously and need to be controlled.  And the blooms seen here are really worth it.  The pictures here were taken of the flowers allowed to trail down the roof of the London Apprentice - the popular pub in Isleworth. For more info check this link