Identification: What is this plant?

these are spreading in a small part of my garden -- I didn't pull them when I initially saw them come up because they didn't strike me as "weeds", yet it is something unfamiliar to me, which I did not plant.... before they blossom and possibly go to seed I would like to id, just in case I want to remove them.

Anyone know what this is?

Thanks.

 

What do the flowers look like when open?
The bud reminds me of Platycodon grandiflorus. Common name Balloon flower.

http://platycodon.net/

http://www.google.co.uk/images?q=pl...&source=og&sa=N&hl=en&tab=wi&biw=1247&bih=528

http://en.wikipedia.org/wiki/Platycodon_grandiflorus

 

I don't know what the flowers look like, none have opened yet, I would imagine it should happen within the next few days. I think you are right though -- looking at the links you send the bud looks exactly like the ones on those sites.

Should find out for sure in a day or two.


Thank you.