May Day's milk maid

Here is one of my favourite flowers from my childhood.  I have always called it milk maid, but it has various names, depending on where you grew up in the UK.  Some know it as cuckooflower.  That would be appropriate here because I could hear the cuckoo calling, some way off, as I was taking these photos.  However, I think this dainty little lady is best known as lady's smock, Cardamine pratensis.