By Gandaco
Cheshire,
United Kingdom 
Thanks for replies -closeup photos herewith
3 Jul, 2010
Answers
There is a white form of S, nemerosa called 'Snow Hill'.
3 Jul, 2010
Many thanks - very grateful
5 Jul, 2010
It's a Salvia probably Salvia nemerosa (a white form of it).
3 Jul, 2010