Description: Primary thallus squamulose, persistent, the squamules whitish to pale greenish grey, white beneath, 1-3(5) mm long, 0.2-1(-2) mm broad, very finely divided and often with an almost coralloid appearance, granulose along the margins. Podetia rather rare, hollow inside, whitish grey to pale grey-brown, 1-10(-20) mm tall, deformed and very irregularly branched, fissured, with gaping holes, often covered by isidioid granules and partly decorticated, with scattered to usually numerous, small, dichotomously divided squamules. Apothecia rare, dark brown, convex, often clustered. Asci 8-spored, clavate, thickened at apex, with a K/I+ blue tholus and a K/I+ strongly blue outer gelatinous sheath, Cladonia-type. Ascospores 1-celled, hyaline, ellipsoid. Pycnidia dark, semi-immersed in the upper part of squamules, with a colourless jelly. Photobiont chlorococcoid. Spot tests: K+ yellow, C-, KC-, P+ yellow-orange, UV-. Chemistry: thamnolic acid and variable amounts of barbatic acid, the latter only in the apothecia.
Note: a mainly temperate, probably holarctic species, normally lignicolous, on stumps, sometimes on basal parts of old trunks, with optimum in old Castanea plantations.