This is a Helleborus niger, commonly also called Christmas rose. It's actually blossoming on our balcony. Strangely it's blossoming in winter and enjoys temperatures around the freezing point. I have no idea how propagation works for them at this temperature.
We bought three of them last year, when I took the picture I use on my blog banner. As this picture shows, they made it through summer. Though, we had to put it in the shade.