Thallus ashy, thin, occasionally with areola-like parts. Apothecia tiny, to 0.4 mm broad, closely adnate; margin thin, of same color as disk or paler; exciple 1+ blue; hyphae of margin radiating; disk rusty brown or rusty yellow to blackish brown, flat; hypothecium pale brownish yellow, 1+ blue; epihymenium dark yellow and with few granules, K+ purple; hymenium 70 µm, hyaline; paraphyses coherent, 1.7 µm, tips to 2-3 µm, branching above and constrictedly septate; spores ellipsoid, polarilocular, 10-18 X 6.5-8.5 µm, septum 4-6 µm.

This species grows on wood or bark; Ahti et al. (1973) reported it on bone. Magnusson (1944c) suggested that it was probably circumpolar but was overlooked on account of its small size. With the inclusion of C. caesiorufella, it is certainly circumpolar arctic.