Red Campion - what has caused this effect ?

Red Campion - what has caused this effect ?

Observation - Red Campion - what has caused this effect ? - UK and Ireland. Description: Clump of Red campion plants (Silene dioica) growing on verge of small country road next to 'normal' ( single flowered) plants. Has anyone seen this effect before? Mutation or environmental effect ?- there has been no spraying nearby

Clump of Red campion plants (Silene dioica) growing on verge of small country road next to 'normal' ( single flowered) plants. Has anyone seen this effect before? Mutation or environmental effect ?- there has been no spraying nearby