loosely or firmly adhering to the ground, erect or decumbent, forming low lax tufts, whitish with a bluish tinge 0.5-1.2 mm thick, bare or with a whitish to roseate thin tomentum, very fragile, sparingly branched with no distinct main axis; phyllocladia
glaucous-white, granular or somewhat elongated, broader toward the apices, dispersed in groups along the pseudopodetia, leaving spaces showing on the axis, conglomerate and angular crustose on some decumbent pseudopodetia; cephalodia
infrequent, on the underside of dorsiventral pseudopodetia, inconspicuous, tuberculiform with granular surface, of the same pale color as the tomentum or brownish violet, containing Nostoc. Central medullary hyphae
parallel, not firmly conglutinate, leptodermatous, 2.5-3.5 µ thick, the lumina 1.3—1.7 µ; the exterior hyphae forming a pale yellowish cylinder of gelatinous, more conglutinate, hyphae 6-10 µ thick, colored pale yellow by KOH; phyllocladia
with cortex 25-45 µ thick, pale yellowish, of firmly conglutinate hyphae, not easily discernible, partly parallel to the outer surface. Apothecia
usually numerous, terminal or sublateral, 1-3 mm broad; disk
dark brown, with long persistent pale margin, lower surface plane, white, tomentose; hypothecium
hyaline, 35-50 µ thick; hymenium
60-70 µ thick; paraphyses
contiguous, 1.5 µ thick, the tips capitate to 4.5 µ brown; asci
cylindrico-clavate, 50-60 x 10-12 µ, 1+ pale blue, hymenial gelatine not colored; spores
8, cylindrico-fusiform with one end narrower, 3-septate, 25-37 x 3-3.5 µ. Conidia
straight, cylindrical 5-6 X 1-1.2 µ.
Reactions: K+ yellow, P— .
Strain 1: atranorin, perlatolic acid, and anziatic acid. This strain occurs in Scandinavia, Iceland, Greenland, and Alaska. The similar appearing S. groenlandicum has the same content as this strain but with the addition of miriquidic acid.
Strain 2: atranorin and lobaric acid. This is the common arctic-alpine strain.
Strain 3: atranorin, stictic and norstictic acids. Lamb (1977) cites only Greenland and Jan Mayen Island for this strain.
Strain 4: only atranorin present. A widely distributed strain.
This species grows in low places below permanent snowbanks and along streams where it is occasionally inundated. It is circumpolar, arctic, and alpine, in our sector distributed from Greenland, trans-Canada to Alaska and south to Colorado and Washington.