I think it is a Japanese Anemone. It will have very attractive tall flowers , probably pink or white , in late summer / autumn.

I think so too.

Definitely is a Japanese anemone. I have them and they look exactly the same. They are very invasive.

thanks folks!
your right about it being invasive lol, i keep trimming it back so it's kinda in the one spot and other bit's have chance to get some light!
i should remove from the geranium page, if i can. xx

It will send out its marching band with runners underground and pop up where it fancies. Keep the hoe going and leave about a foot all round free of plants. It is a lovely late blooming plant but has some very bossy habits. Even if you 'take it out' bits will be lurking underground and thumb their noses at you. Worth keeping though as long as YOU boss IT about.