Meadow Buttercup (Ranunculus acris) gone creamy-lemony

Found growing in Shaw Forest Park, Swindon, on June 5th. (I also saw Tall Fescue and Salsify.)

This is a lemony-creamy variant of Ranunculus acris, found growing among the more usual yellow ones.  (It looked similar in colour, though not in habit or floriferousness, to the garden cultivar 'Citrinus'.)