It's Solomon's Seal, Polygonatum x hybridum is the usual one but there are others.
They like to grown in shade, I have one in a raised bed around a large horse chestnut tree with a lot of leafy compost. They take a long time to establish, once mine got going well it was eaten by Solomons-seal Sawfly larvae! I saw it had one weak stem in flower today, oh well.
http://www.saga.co.uk/magazine...