Thallus 3-5(-8) cm tall, mostly subpendant to erect, flaccid, main branches 1.5-2 mm diam., originating over the whole of the thallus length with relatively few, thinner, side branches which often arise at ± right angles from these main branches. Primary branches much elongate, distinct, thick, fusiform (often divided into long, somewhat inflated segments), often constricted and annulate where they join the main stem, giving a characteristic overall combed appearance. Fibrils few or absent, axils at an angle of 60-90°. Thallus surface very pale grey to green, often ± pellucid when wet, brown to jet-black for 1-2 mm above the ± attenuated base, shiny (resembling broken glass), smooth. Papillae usually numerous, evenly and densely distributed, low, broader than high, often inconspicuous. Soralia even, ± flat to slightly concave with a distinct rim, large, conspicuous, rounded, discrete, widely spaced. Isidiomorphs irregularly present, mostly absent on mature soralia. Medulla lax.
Anamorph: not known.
Teleomorph: not known.
Chemistry: thallus C–, K+ yellow-red, KC–, Pd+ red (usnic, stictic, menegazziaic and ± cryptostictic, ± norstictic and ± constictic acids).