Oxalis oregonum

A very striking woodland species from western USA, with vivid pink flowers over somewhat shiny lustrous green leaves. A bit like our native wood sorrel (O.acetosella) but two to three times bigger in all parts. 

This is a remarkably pretty creeping plant that is not deep rooted or weedy, but runs on rhizomes just on or under the surface. Best of all it's an excellent addition to the list of plants that thrive in dry shade (as do many western US plants) making a nice solid ground cover even under evergreen shrubs.
£8