Diffractaic acid (K–, Pd–, C+ pale yellow, CK+ yellow to yellow-orange) is present as a main substance, barbatic and squamatic acids as accessory substances; amount of unidentified pink and/or yellow pigments varies.

Distinguished by the coarse-texured thallus and unique chemistry (presence of diffractaic acid); pink medulla and axis are of help in determination of juvenile specimens (James 2003).

Europe (map legend)
Corticolous, on old trees with a rather acid bark in well-lit situations (Purvis et al. 1992, Diederich et al. 2008). The species is widely distributed both in the northern and southern hemispheres; reported in Europe: Austria, Belgium, Bulgaria, Czech Republic (probably extinct), Northern France, Germany, Great Britain, Hungary, Italy, Ireland, Latvia, Luxembourg (probably extinct), Netherlands (probably extinct), Poland, Portugal, Romania, Slovakia (probably extinct), Slovenia, Spain, Sweden (probably extinct), Switzerland, Ukraine.

Estonia
Not known in Estonia or Lithuania but reported from north-eastern Latvia, Donikava, on conifers (Piterāns 1982, 2001). Occurrence in southern Estonia can be presumed (Tõrra & Randlane 2007).