White buttercups

White buttercups

Observation - White buttercups - UK and Ireland. Description: Except for its colour it is identical to the other yellow buttercups which are abundant in the vicinity. I can't understand why it is white when all the others are yellow. They are on the cliff-top at north head St. Bees, Cumbria

Except for its colour it is identical to the other yellow buttercups which are abundant in the vicinity. I can't understand why it is white when all the others are yellow.
They are on the cliff-top at north head St. Bees, Cumbria