brought in with the compost!!!

Had the contents of my mates compost bins and now i have this little devil popping up all over the place

It's leaves are shaped like bindweed but are darker and shinier. It grows about 4" high - she thinks it might die down in Summer?????????
Any ideas anyone?? Should I be eliminating it from my borders or should I leave it?

 

I do believe this to be Calystegia sepium, Hedge bindweed.
You say it has only grown to 10cm, but did not say if it has climbed up any shrub near to it.
If it dose reach an object and climbs up it, it would confirm my suspicions. Regards, Fonzie.

 

Personally Windy I'd give anything that resembled bindweed the heave-ho. Can't see anything like that popping its clogs in summer. More like the opposite!

 

Oh b....er it looks like lesser celandine. I have just checked my Oxford book of wild flowers for leaf shape and it does have shiney leaf which i knew but is also heart shaped. The height is right and it does die down in summer.
It will spread from little bulbils and is a sod to get rid of once you introduce it. You can tread the bulbils around on the soles of your shoes. If you dig it up, carefully transfer soil into a bucket and dispose of carefully. How on earth did it come in on compost?
I have a clump on the stream bank below my wire fence that I am watching carefully - obviously they just washed down the stream in the floods. I am afraid it is one that is goiing to give you a bit of work.

 

Just looked at Keble Martin and that seems to confirm my suspicion, with the notch at the bottom of the leaf. It is one of those things that if I saw it in the flesh I could be quite definite.
Do the leaf stems all come from a small crown at ground level? Cause that is how lesser celandine grows? Flowers fairly soon, in my experience before wild primrose, and I think the leaves are yellowing by May.