Scoliciosporum abietinum

Scoliciosporum abietinum is a little-known species of crustose lichen in the family Scoliciosporaceae. This tiny lichen forms minute white to grey-white crusty patches only 0.3–0.6 mm across that grow directly on the living needles and leaves of conifer trees such as grand fir and western redcedar. It is found in the humid inland rainforests of southern British Columbia and northwestern Montana, where only four collections have been made, making it both rare and easily overlooked due to its extremely small size....read more on Wikipedia.