Blue Anemone
Anemone apennina

This shot was taken within the grounds of Battle Abbey, East Sussex, at the site of the Battle of Hastings. The blue anemone (also known as the 'windflower') is a carpeting, spring flowering perennial with deeply cut foliage. White and pink variants are more common. The genus anemone are poisonous, especially to livestock, because of the presence of the narcotic Anemonin. Many thanks to John Crellin for identifying this for me: