Description: Primary thallus squamulose, persistent, the squamules ascending, scattered or forming small mats, small to middle-sized, up to 3 mm long, 1-2 mm wide, crenate or slightly lobed, olivaceous green to brownish green above, white beneath, sometimes with pale orange patches near the attachment point. Podetia brownish grey to greenish grey, subcylindrical to bacilliform, 1-10 mm tall (rarely more, up to 40 mm), 0.5-1 mm thick, simple or sparingly branched in upper part, corticate or rarely ecorticate in upper part, the cortex variable, from smooth and unbroken to areolate, sometimes squamulose or granulose, the granules simulating very coarse soredia. Apothecia frequent, scarlet red, terminal, often forming conspicuous clusters. Asci 8-spored, clavate, thickened at apex, with a K/I+ blue tholus and a K/I+ strongly blue outer gelatinous sheath, Cladonia-type. Ascospores 1-celled, hyaline, ellipsoid. Pycnidia scarlet red, distinctly stalked, most common on the primary squamules, rarer on podetia, with a red jelly. Conidia cylindrical. Photobiont chlorococcoid. Spot tests: K- or rarely K+ yellow, C-, KC-, P- or rarely P+ yellow, UV- (rarely UV+ bluish). Chemistry: the most common chemotype has barbatic and didymic acids, a rarer chemotype with thamnolic and didimyc acid has been also reported from Northern Europe; rhodocladonic acid in apothecia and pycnidia.
Note: a circumboreal-montane species found on organic soil and peat, but also on sand, more rarely on lignum or at the base of trunks, with optimum in the subalpine belt of the Alps.