Pseudevernia furfuracea, commonly known as tree moss, is a lichenized species of fungus that grows on the bark of firs and pines.

[4] The preferred growing surfaces for P. furfuracea are the so-called "nutrient poor" bark trees, including birch, pine and spruce.

[6] Large amounts of tree moss (approximately 1900 tons in 1997) are processed in Grasse, France for the perfume industry.

[14] Because specimens of P. furfuracea tend to bioaccumulate heavy metals like Cr, Zn, Cd, Pb, Ni, Fe, Mn and Cu proportional to their concentration in airborne particulates, they may be used as a biomonitor of air quality,[15][16][17] although it has been noted that both trace metal accumulation[18] and major element accumulation[19] is partly dependent on the hydration level of the specimen.

[24] Of these compounds, atranorin showed the highest inhibition of proteolytic enzymes trypsin and porcine pancreatic elastase.

[24] Research suggests that the biosynthesis of both atranorin and physodic acid is influenced by the cooperation of epiphytic bacteria.