This is a bumper year for White Deadnettle (Lamium album). It's a familiar wayside weed/wildflower but I have never before seen so much of it growing all along the hedge bottoms and indeed all over the place. 

 Like other members of the Lamiaceae family the flowers remind me of a clam shell. Bumblebees are able to shoulder their way in and drink the nectar with their long tongues. An alternative family name is Labiate in reference to the flowers having an upper and lower lip (Labia meaning lip in Latin) which is another way of putting it.