Water Avens (Geum rivale). This is a riverside plant; it can take a bit of shade but it needs a damp spot. I grow it in an old zinc wash tub to retain some moisture in the soil with a few holes drilled in the bottom so it doesn't get too swampy. Big bumblebees favour the nodding flowers which nod even more as the stalks bend with the weight of the bee as it clings upside down to get at the nectar.