World distribution: The species is known from Europe and Macaronesia (Jørgensen 1978). In Europe, it is distributed along the western coast from Portugal to Norway; in addition there are a few sites in oceanic northwest Italy. In northwest Europe, its distribution is disjunct with occurrences in western Norway and western Scotland. In Fennoscandia, the species is known only from Norway
Ecology: Results. The species has been found on steep rock (2) and on bark of Fraxinus excelsior (1), in northern (1) and western (1) aspects. Discussion. Outside Norway the species appears mainly to be corticolous (Jørgensen 1978, Purvis 1992e). In the British Isles Parmeliella testacea is locally abundant on moss covered broad-leaved trees in moist, sheltered woodlands (Purvis 1992e)
Threats: Results. It was regarded as extinct due to road improvement in locality 236. Recorded threats in its two present sites were lack of pollarding (2407) and possible building on the site (1482). Discussion. Random extinction is a general threat to small populations
Status: The species was present, but sparse, in one (1482) of the two old sites which were investigated; it was regarded as extinct in the other (236). The species was abundant on Fraxinus excelsior at locality 2407 in 1985 (Arvidsson 1986). Locality 2407 is protected as a nature reserve. No new localities were discovered
Specimens in other herbaria, litterature, etc.