Physconia grisea (Lam.) Poelt subsp. griseaThallus foliose, heteromerous, dorsiventral, narrow-lobed, forming regular to irregular up to 5(-8) cm wide rosettes. Lobes (1-)2-3 mm wide, slightly broader at tips, radiating and partly overlapping, with a coarse white pruina at least in apical parts, flat to irregularly concave, grey-brown to brown, with primarily marginal, elongate soralia tending to become laminal in older parts, the soredia coarsely granular to almost isidioid. Lower surface whitish in marginal parts, pale brown in central parts, with mostly simple, whitish to pale brown rhizines. Upper cortex paraplectenchymatous; medulla white; lower cortex prosoplectenchymatous, with hyphae oriented parallel to the long axis of lobes. Apothecia rare, lecanorine, 1-3 mm across, with a pruinose disc and a sorediate thalline margin. Epithecium brown; hymenium and hypothecium colourless; paraphyses slender, simple or forked in upper part, the apical cells clavate, with a thin, dark brown cap. Asci 8-spored, clavate, the K/I+ blue tholus penetrated by a faintly amyloid apical cushion with parallel or diverging flanks, the wall K/I-, surrounded by a K/I+ blue outer layer, <i>Lecanora</i>-type. Ascospores 1-septate, brown, ellipsoid, (22-)25-32(-34) x (12-)14-17(-19) µm, thickened at septum but not at apices, <i>Physconia</i>-type. Pycnidia frequent, immersed, inconspicuous. Conidia 4-7 x 1-2 µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-. Chemistry: medulla with four unidentified lichen substances. 
