This is not a spectacular plant, you will probably need to click on the photo to enlarge it to see the tiny white flowers. It does however have a delightful name: Enchanter's Nightshade. The Latin name is Circaea lutetiana. Circe was an enchantress in Greek mythology.
 It has spread through a damp shady border alongside the house where I have tried several groundcover plants which haven't flourished. And lo! As if by magic Enchanter's Nightshade has self-seeded from who knows where and done the trick.