Gyalectaria diluta

Gyalectaria diluta is a species of crustose lichen in the family Coccotremataceae, first found in inland rainforests of British Columbia. This pale, crust-forming lichen grows on the bark of conifer trees in very humid old-growth forests, where it forms small patches that bleach the underlying bark to whitish or pale green-grey colours. It is found from British Columbia to Montana and Idaho, typically growing on smooth bark of young cedar saplings beneath mature forest canopies that have remained undisturbed for centuries....read more on Wikipedia.