Lamiums are sometimes called deadnettles due to some of the 40 or so species having a resemblance to stinging nettles (without the sting). Above is the yellow flowered Lamium galeobdolon. The straight species has plain green leaves and is found in ancient woodlands; indeed its presence is generally an indicator that the woodland is ancient. There are also varieties with a frosty white variegation of the leaves (as above) which is a natural variation in Eastern Europe and Russia and sold under various names over here.
 Gardening books sometimes warn against planting these due to their invasive tendencies. I know several gardens (including here) where it has it has run to large patches but is this a problem? It does well in part shade and forms an excellent groundcover of attractive foliage all year round.
 In spring it throws up spiky clusters of yellow which are a magnet for bumblebees. They shoulder their way into the clam-like flowers forcing them open to feed on the nectar within.