Thallus: squamules (0.5-) 1-2 (-3) mm diam., ascending, clustered or crowded, often ± imbricate, spreading, sometimes forming a nodulose crust-like cover, incised or divided, ± tumid (especially on the margins), the upper surface pale olive brownish to medium brown, green-olive when wet, underside dark brown to blackish, paler towards the margins. Thallus 200-300 (-400) µm thick, upper cortex very thin (often only 1-2 cells thick), composed of globose cells, the epinecral layer up to 30 µm thick. Medulla composed of thin-walled globose cells, lower cortex not developed but the lower surface often pigmented. Rhizoidal hyphae brown, in the central part of the thallus usually aggregated to form a tuft or rhizine-like attachment organ to ca 400 µm long and 200 µm diam. Photobiont Trebouxia-like. Anamorph: not known. Teleomorph: ascomata perithecia, frequent, 1-5 per squamule, 200-300 µm diam., immersed with a ± elevated, dark ostiole. Involucrellum absent. Peridium pale to blackish brown, composed of tangentially arranged, ± elongate cells, more strongly pigmented around the ostiole. Interascal tissue absent, but the ostiole is lined with periphyses 20-30 x 2-3 µm in size. Asci 50-70 x 10-14 µm, clavate, thin-walled, the apical region slightly thickened when young with a small ocular chamber, 8-spored. Ascospores arranged biseriately, (12-)14-20 × 5.5-7.5 μm, ellipsoidal to slightly ovoid or fusiform, at least usually 1-septate, sometimes slightly constricted at the septum, hyaline, thin- and smooth-walled, without an epispore, gelatinous sheath or appendages.