Physconia detersa (Nyl.) Poelt
Parmelia pulverulenta var. detersa Nyl.
Physcia detersa (Nyl.) Nyl.
Thallus foliose formed by radiating lobes 2-3 mm wide forming a rosette 3-6 cm in diameter, upper surface shiny, purplish-brown, brownish-gray if dry, greenish-brown if wet, the lobes often have the end powdery and always white granular marginal soralia with bluish reflections, white medulla; underside black in the center, blackish-brown at the margin with black scaly rhizines. Apothecia rare, 1-3 mm in diameter, sorediate margin. Spores 1- septate, 27-32 x 16-20 µm according to the literature. C-, K-, KC-, P-. Mountain species found on the bark of trees and more rarely on mossy rocks. Species very similar to Physconia perisidiosa (and often confused) which has marginal and labriform soralia and which is less mountainous.