E-Flora BC: Electronic Atlas of the Flora of British Columbia

Species description:
Thallus small to medium but not minute; lobes averaging to more than 1.5 mm wide, always dorsiventral; isidia present or absent, distinctly wrinkled upper surface AND
Lobe margins naked; isidia, if present, naked (upper surface, however, occasionally hairy) AND
Lobes broad or, if elongate, then never both erect and terminating in distinctly swollen tips; lobe tips averaging to less than 0.2 mm thick when moist, seldom strongly wrinkled when dry; habitat and distribution various AND
Lower surface densely white-woolly throughout (except often naked along lobe margins) AND
Upper surface smooth or rarely in part bearing few scattered wrinkles; isidia not at all dimpled at tips; distribution various AND
Upper surface distinctly greyish (check sheltered lobes), sometimes in part covered in short whitish hairs; mature isidia cylindrical or branched/coralloid

Comments:
Specimens having minute white hairs over the upper surface can be referred to var. hirsutum (Sierk) P.M. Jørg.