Description: Primary thallus squamulose, persistent or rarely disappearing, the squamules indented, 2-10 mm long, grey green above, white beneath, esorediate but sometimes granulose on the lower surface. Podetia extremely variable in shape and size, hollow inside, greenish grey to brown, not melanotic at base, 3-7(-14) cm tall, 0.5-2(-5) mm thick, simple or sparingly branched with open axils, usually expanded in upper parts to form gaping funnels which may proliferate radially, the surface often largely ecorticate exposing the stereome, more or less densely covered with microsquamules, squamules and granules, esorediate. Apothecia infrequent, brown, convex, located at the top of podetia or at the margin of funnels, often clustered. 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 dark, semi-immersed on podetial tips, rarely on basal squamules, with a red or colourless jelly. Conidia bacilliform. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV+ white. Chemistry: squamatic acid and variable amounts of barbatic acid (especially when fertile).
Note: a widespread holarctic lichen found on organic substrata in sheltered situations, rarely on bark, on basal parts of trunks; a very polymorphic taxon, which needs further study. Older records reported by Nimis (1993: 244) require confirmation.
Growth form: Fruticose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by isidia, or isidia-like structures (e.g. schizidia)