Lepraria pacifica, the Pacific dust lichen, is a whitish-blue-green leprose crustose lichen that grows on its substrate like patches of granular, caked-up, mealy dust grains.

[1][2] The main vegetative body (thallus) is made of patches of soredia, little balls of algae wrapped in fungus.

[1] It grows on rock, soil, and bark, along the pacific coast of North America, from Coastal British Columbia to populations found in southern California, and in and near Yosemite National Park in the Sierra Nevada range.

[1][2] It is usually corticolous (grows on bark), and occurs only in western North America.

[1] It may be confused with L. crassissima and L. incana because of its similar chemistry, but it occurs in different biogeography and ecology.