The Stinking Hellebores (Hellebore foetidus) towards the back of the garden have been flowering since before Christmas. Further back the drift of naturalized Snowdrops illuminates the green shade (hmm green shade, I've heard that phrase before somewhere).
 Both attract bees on sunny days even in the cool temperatures of February like this bumblebee making its way round the Hellebores. NB They have no scent that I can discern and only a foetid smell if the foliage is crushed. The bees must have a way of being alerted to them though, either by some scent or the vivid lime green flowers (or both).