Chemistry is variable, with several chemotypes reported: (1) chemotype with norstictic and salazinic acids (K+ red, Pd+ yellow to orange) as main compounds plus other compounds of the stictic acid complex and protocetraric acid as accessory substances is the most common in Fennoscandia; (2) with norstictic acid as main substance (K+ red, Pd+ orange) plus stictic acid complex as accessories is widely known in Fennoscandia (Halonen et al. 1999) and Great Britain (James 2003); (3) chemotype with psoromic acid (K–, Pd+ yellow) and accessory substances is rare in Great Britain (Clerc 1992, James 2003); (4) chemotype without medullary substances (K–, Pd–) has been reported as rare in East Fennoscandia (Halonen et al. 1999).
In Estonia chemotype (1) is common (n=20) and chemotype (2) is rare (n=3) (Tõrra & Randlane 2007).

Distinction from closely related taxa see under U. fulvoreagens.

Europe (map legend)
Corticolous. Reported in Europe: Austria, Bulgaria, Czech Republic, Denmark, Estonia, Finland, Germany, Great Britain, Hungary, Ireland, Italy, Latvia, Lithuania, Norway, Poland, Romania, Russia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Ukraine.

Estonia
72% of examined specimens grow on coniferous trees (Picea and Pinus) and 21% on Betula; other phorophytes are of less importance. Very frequent in Estonia (80 specimens), reported mainly on the northern coast and in south-eastern region of Estonia (Tõrra & Randlane 2007).