What weed is this?

I have a fair few of these in the lawn and I can't seem to shift them. In periods of wet weather for a week when it's not possible to mow they grow very fast. Around 4 or 5".

 

I'm not sure what that is with just a single leaf, is it possible to see the whole plant please Dan?

 

That's it sheal. They come up like that. I'm off to cut the lawn in a bit so will grab some more photos.

 

Creeping Buttercup

 

Does it actually matter what weed it is?
If its a weed, in the lawn, then weed and feed kills most, although it might be getting a bit late now to use that.

 

It does matter to some of us Pete. It may be to late for feeding lawns but I'll be putting down weed killer tomorrow, I'm still fighting dandelions and creeping buttercup.