Thallus grey-green when dry, bright green when wet, forming a diffuse crust of goniocysts over the substrate and often forming a collar surrounding each ascoma. Soralia scattered, diffuse, concolorous with the thallus; soredia 20-40 μm diam., surface hyphae of ± isodiametric and often projecting hyaline cells. Photobiont trebouxioid. Anamorph: no information available. Teleomorph: ascomata perithecia, 200-450 µm diam., 25-75% immersed in the thallus. Peridium with irregularly distributed pigmented areas, thus tending to break up into ‘plates’ in squash preparations. Interascal tissue not seen. Asci 78-105 x 23-28 µm, ± cylindrical and very thick-walled when young, clavate and ± thin-walled when mature, apparently fissitunicate, not staining in iodine, 8-spored. Ascospores 31-37 (-39) × 6.5-8 μm, ± cylindrical, the apices rounded to obtuse, (5-)7-septate, the septa occasionally oblique, fairly thick-walled, smooth, without a perispore, gelatinous sheath or appendages. Chemisrty: no lichen products detected by TLC.