Do you know what this pretty plant is?

This has appeared for the last couple of years: any ideas what it might be?

?Erigeron?

Looks like a form of Centaurea/Knapweed.

Thanks for your advice.  Centaurea looks the most likely candidate, except for the leaves... when the weather improves I will take a better picture.

It might be a Thalictrum

http://uk.images.search.yahoo.com/search/images?_adv_prop=image&fr=slv8-msgr&va=thalictrum

Pam x

I also think it's a Thalictrum. How tall is it and do the plants grow more or less singly or are they somewhat mat-forming?

Looks like my Thalictrum aquilegifolium. Has yours got leaves that look like the ones on an aquilegia plant? Hence the name!

Got it: thanks so much.  Yes, it's a thalictrum aquilegifolium, which is probably why I kept expecting it to turn into an aquilegia.  This is a brilliant forum: we should get together and make a virtual garden!

Glad I could help smallswan. I agree this is brilliant. I love the way everyone helps everyone else. We all learn stuff over the years, but we still need to ask advice with new plants or problems. I just wish I could meet some of these interesting people!

Maybe when we go to flower shows we should wear a badge with our forum name on it, then we could identify each other!

My eyesight is gerring worse. Should have known this, I spent half the afternoon pulling out unwanted seedlings of it.