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 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 naked or bearing scattered tufts of hair at points of attachment, never distinctly woolly AND Isidia and/or lobules present over upper surface AND Thallus distinctly thin, averaging to less than 0.1 mm thick when moist; distribution various AND Isidia cylindrical throughout AND Upper surface bluish grey throughout; over trees (rare over mossy rock); restricted to humid localities; rare
Comments: Notes: Although Sierk (1964) claims that L. cyanescens “is the most common species of Leptogium in North America,” it is obviously very rare in B.C.
