In The Garden: ID needed on Abbey white flower

Hi, I'm new to this forum, :-) I recently went to the fantastic Forde Abbey gardens in Somerset (United Kingdom), and got a good picture of a lovely white flower.

I've been searching for an ID, but have been unable to come up with anything, :-( I'm hoping someone who knows a bit more about plants than I could help me with a species ID.

Thanks!

Maedin T.

 

http://images.google.com/images?hl=...cosmos+bipinnatus&btnG=Search+images&aq=f&oq=

 

That was fast! Thank you, Ron, :-)