Cardamine pratensis aka Lady's Smock or Cuckoo Flower.

Once again, thank you very much, Owdboggy! Now that I know this is Cardamine pratensis (Cuckoo flower, Lady's smock) I can look out for it.

It is a food plant for orange tip butterflies. The female [minus orange tips on its wings] lays her eggs on these and many other native flowers.

Thanks, Eileen, but I don't remember ever having seen an Orange Tip butterfly here. I've seen plenty of Cabbage butterflies (both species), lots of Peacocks, many Tortoiseshells + a few I can't identify, like a small blue one.

Round here they seem to like living in damp meadows if that's any help. (the flowers not the orange tips...)I found a very small one on the lawn today - not sure what that says about the lawn...

"I found a very small one on the lawn today - not sure what that says about the lawn..."

Perhaps it needs extra drainage? Holes made with a garden fork are supposed to help aerate the lawn. Especially if then filled with sharp sand. If it's only a small area perhaps that might help but if it's a big area then that would be too much.

Thanks Balcony! Very good advice - it certainly is time the lawn was spiked and scarified - the Spring here has been so appallingly wet everywhere that I think most lawns here would qualify as damp meadows... But to tell you the truth I was thrilled to find the cuckoo flower (loved those since I was very small) and also a few little self seeded ragged robins, which I'm going to try to transplant to the edge of the pond where one appeared last year.. Even though they are only about three or four inches high they were trying to flower! OH carefully mowed round them for me.... Do you think I'm past redemption?

Would it be too much of an inconvenience to leave things as they are at present & just let the grass grow long so that wild flowers can grow naturally? It's becoming a bit of a trend not to cut lawns back so much & there's even a 'No Mow May' where the grass is left to grow without being cut during the month of May.