Description: Primary thallus squamulose, persistent or evanescent, the squamules 1.5-3(-4) mm long 1-2 mm broad, irregularly divided, usually becoming concave, glaucescent or olive-green on upper side, white beneath, often darkening towards the attachment point. Podetia frequent, bacilliform, hollow inside with a very narrow, <10 μm wide central canal, pale grey to whitish grey, not melanotic at base, 4-10(-15) mm tall, 0.5-1 mm thick, usually cupless, sometimes with a few apical branches and open axils, with a verruculose cortex, the warts dispersed, tending to become subsquamulose-phyllidiate. Apothecia very rare, dark brown, convex, terminal. 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 rare, mostly on primary squamules, constricted at base, with a colourless jelly. Conidia bacilliform. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV+ ice-blue. Chemistry: perlatolic acid and three unknown compounds.
Note: an arctic-alpine to boreal-montane, circumpolar species found on mineral, more rarely on organic soil and rotting wood in open habitats, restricted to siliceous areas in the Alps.
Growth form: Fruticose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)