Ovstedal, D. O., & Smith, R. L. (2001). Lichens of Antarctica and South Georgia: a guide to their identification and ecology. Cambridge University Press.
Thallus white to pale buff, crustose to subeffigurate, areolate to 5 cm diam. Apothecia black, sessile, to 1 mm diam, when young with thin, true margin; when old margin excluded. Hymenium 90-100 µm high, upper part green-brown. Exciple and hypothecium black. Asci 8-spored. Ascospores halonate, elliptic, 15-24 X 10-14 um. Medulla K/I-.
Ecology: On calcareous rock, with Lecanora nylanderiana and Thelidium austro-atlanticus. 50-100 m.
Distribution: Bipolar. North and Central Europe, North America. Antarctic South Orkney Is, South Shetland Is, Antarctic Peninsula.