Lichens are composite organisms composed of fungal species in a symbiotic relationship with algae and/or cyanobacteria. Although lichens are classified and named based on the fungal component, they are here presented separately from fungi for convenience of access.
Description: Thallus yellowish-white to greenish-grey; lirellae black and slightly raised, 1-7 mm long, 0.15-0.3 mm wide.
Distribution: West of Cascades crest in Washington (largely coastal); Alaska to northern California, east of Mississippi River; Ontario, Quebec, Newfoundland.
Habitat: Usually in partial shade.
Substrate: On bark of all types of trees.