Rhododendron albiflorum
Ericaceae Dicot
white rhododendron, Cascade azalea
Rhododendron
from the Greek: rhodos, "rose", and dendron, "tree")
Rainbow Lake, Mt. Baker-Snoqualmie National Forest
King County, Washington, USA
i083008 038
Sorry, picture is not very good. This is a white flowered shrub in a tiny meadow at 4,300 feet in the Olympics.