Ragged robin

Lychnis flos-cuculi, commonly called Ragged Robin, is a herbaceous perennial plant in the family Caryophyllaceae. It is species is native to Europe, where it is found along roads and in wet meadows and pastures. In Britain it has declined in numbers because of modern farming techniques and draining of wet-lands and is no longer common.
http://en.wikipedia.org/wiki/Lychnis_flos-cuculi