Thallus tufted, 1.5-5 cm tall, ± erect, forming spreading tufts or cushions, often richly and irregularly branched. Main branches rather coarse, 0.8-1.5 mm diam., rounded, branching unequally dichotomous, with few to very numerous thinner side branches, often appearing coralloid, with blunt apices, grey (in shade), pale brown or brown-grey, sometimes strongly tinged red-brown, smooth.
Anamorph: no information available.
Telemorph: ascomata apothecia, infrequent, 1-3 mm diam. Ascospores 8-12 × 7-11 μm, broadly ellipsoidal, greenish to dark violet-blue-black.
Chemistry: medulla C–, K± yellow, KC–, I+ blue, Pd± yellow, UV+ blue-white (sphaerophorin, squamatic, ± thamnolic and ± hypothamnolic acids).
Assessed by Woods & Coppins (2012) as of Least Concern.
Characterized by the distinct, coarse, rounded main branches and thinner, smaller secondary branches, a tendency to form lax to compacted, often ± pale or reddish brown tufts and the I+ blue medulla. The iodine reaction may be faint or absent in old herbarium specimens.
Locally abundant. N Scotland (Highlands), Ireland, extending locally to England & C & N Wales. BLS map here.
On rocks, often amongst other lichens and mosses, also on acid-barked, mossy trees more rarely on moorland soils.