Anemonoides sylvestris

Anemonoides sylvestris (syn. Anemone sylvestris), known as snowdrop anemone or snowdrop windflower, is a perennial plant flowering in spring, native to meadows and dry deciduous woodlands of central and western Europe and temperate Asia. It forms spreading patches, sometimes aggressively spreading.

Another name is wood anemone, but this more commonly refers to the European A. nemorosa or the North American A. quinquefolia.