Thallus foliose, lobate, firmly attached centrally, ± free at margins, spreading, to 12 cm diam., corticolous rarely terricolous or muscicolous. Lobes irregularly to dichotomously branched, margins entire, not sorediate or phyllidiate, free and subascendent. Upper surface distinctly reticulate-faveolate with conspicuous faveolae and strongly developed interconnecting ridges which are often isidiate, matt, dark brownish-black when wet, olive-brown or buff when dry, lacking soredia, phyllidia or pseudocyphellae. Isidia laminal, mainly on reticulate ridges, simple, rather fragile, terete, becoming coralloid-branched with age, less than 0.5 mm tall, concolorous with thallus, not becoming sorediate. Medulla white. Lower surface with marked, pale brown, bullate, naked areas separated by a network of dark tomentum which extends to the margin, rhizines few to numerous, simple or squarrose, dark brown, central. Apothecia and pycnidia not seen in New Zealand material. Chemistry: Cortex K-; medulla K-, C-, KC-, Pd-. Thelephoric acid and stictane-3β,22α-diol.