Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus rather thick, abruptly margined but not limited by a hypothallus; areolate, areolae 1-2 mm broad, deeply chinky and also deeply subdivided into smaller verruculose to columnar units, pale ashy to slightly darker ashy, lacking soredia or isidia. Apothecia becoming large, to 2 mm broad, sessile and with base constricted, becoming raised over thallus; exciple paraplecten-chymatous, pale violet-brown, interior hyaline and blending into hyaline hypothecium; disk black, dull, epruinose, flat and with distinct margin, becoming crenulate to dissected, sometimes quite irregular; hypothecium hyaline; epithecium granulose, brown-olive to bluish brown; hymenium 100-125 μm, upper part bluish brown or olive; paraphyses conglutinate, slender with tips scarcely thicker; asci inflated; spores large, broadly ellipsoid, 17-20 X 8-12 μm.
Growing on basalt rock, this species is known only from the type locality, Ymeroya, Cape Humboldt, northeastern Greenland.
There is a strong resemblance of this species to very large specimens of L. lapicida. But the spores are much larger, the reaction of the upper hymenium blue-green instead of red with HN03, and the medulla is I— rather than 1+.