Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus thick and knotted, continuous, rounded and piled up, white or yellowish white, smooth and shining, sometimes roseate or brownish, occasionally slightly pruinose, lacking soredia or isidia. Fertile verrucae like the thallus, the shapes from simple and hemispherical to conglomerate masses with many ostioles but the base narrowed, even forming multiperforate sheets. Apothecia immersed, ostioles usually black, sometimes with white border; hypothecium hyaline to brownish; epithecium hyaline or dark, K— or infrequently weakly K+ violet; hymenium hyaline to pink; asci cylindrical; spores 2 (occasionally 1, rarely 3 or 4), uniseriate, oval to cylindrical, double-walled, outer wall 1-4 μm thick, inner 5-19 μm, usually smooth, often with concentrically laminated ends (rarely rough or radially grooved), with irregular thickening of end wall, 160-245 x 38-75 μm.