Who said Umbelliferas weren't interesting? I think Cow Parsley has given them a bad name, being so apparently common. Things will change when Rape usurps Cow Parsley in our hedgerows.
But this is Upright Hedge-Parsley, Torilis japonica, which takes over from Cow Parsley on the roadsides and hedges from July to early September. This one was growing in a protected spot at the base of a wall overrun with Vinca minor.