Pinus parviflora 'Tempelhof'
Humphrey Welch and Gordon Haddow state in 'The World Checklist of Conifers' that this is a ston-growing cultivar with dark Blue-silver leaves.
There is also a very good picture of this cultivar in Conifers the Illustrated Encyclopedia
This pictue was taken in 2001 at the Botanical Gardens of Montreal, Quebec, Canada.
Photo by Ken Church