Thallus rather loosely attached, ± orbicular to spreading, 5-10(-15) cm diam. Lobes linear-elongate, 0.5-1.2 cm diam., and 3-6 cm long, margins entire, sinuous, without phyllidia, isidia or soredia. Upper surface dark grey-blue or blackish when wet, pale greyish-fawn when dry and margins suffused red- brown, white, reticulate maculae (×10 lens) and larger algal-free areas conspicuous at margins, shallowly undulate, without soredia or isidia, not reticulate-faveolate, matt or shining, pseudocyphellate. Pseudocyphellae white, minute, punctiform, scattered. Medulla white. Photobiont blue-green. Lower surface tomentose to margins, pale whitish or buff at margins, darkening towards centre. Tomentum rather thin, pale to dark brown, silky. Pseudocyphellae white, scattered, prominent, round to irregular, 0.1-1.0 mm diam., with a prominent, slightly raised pale buff, glossy margin, decorticate area excavate, coarsely granular. Apothecia rare (only one seen), marginal, sub-pedicellate 0.8 mm diam., disc concave, red-brown, shining, epruinose, thalline exciple well-developed, pale flesh-coloured, coarsely areolate-scabrid, inflexed, obscuring disc. Ascospores not seen. Chemistry: 7β-acetoxy-hopan-22-ol, and hopane-15α,22-diol (Wilkins and James loc. cit., Code A).