Thallus prostrate, straggling, forming matts, closely attached to substrate, often dying from centre and forming rosettes, to 12 cm broad, rarely exceeding 1 cm in height, branching frequent from base, isotomic-dichotomous, occasionally isotomic-trichotomous, branches often inter-woven, terete to slightly dorsiventrally compressed, to 0.2 mm diam., usually concolorous but sometimes paler at base, cervine brown, dark brown to black, shining or occasionally matt, the whole thallus with a very wiry texture. Apothecia occasional, lateral, thalline exciple concolorous with thallus, smooth, dentate to ciliate marginally, disc matt, greyish-black or brown, plane but becoming convex with age, to 5.5 mm diam. Ascospores 7-12 × 6-8 µm. Pycnidia occasional, on tubercules, particularly frequent near axils, black, to 0.4 mm diam. Conidia 5-7 × 1 µm.