Established plant or rip it out weed?

It's very close to the ground growing outwards. Think there is some grass growing up in between it as well.

 

I think it's Lesser Trefoil. Bit of a pest if you get it in a lawn, but not such a problem elsewhere as it is very low growing and will get shaded out by larger plants.

The other possibility is clover. As above, not good news if you want a pristine, weed free lawn, although it can be beneficial to grass growth and clover flowers are much loved by bees.

 

Its in my flower bed. I shall work round it if its worth keeping.

 

Think it looks like lesser trefoil.