Wood Anemone

Anemone nemorosa
Grows in woodland. Especially ancient woodland. Here it is growing in our garden. But the we believe our garden was coppiced woodland before our house was built in 1965.
The way it spreads is a little puzzling. Apparently its seed is rarely viable in this country and it spreads underground by extension of its roots. One book says this is a very slow process taking a hundred years to expand by six feet. Ours seems to have expanded more quickly than that.