Thallus
Crustose, up to 8 cm, lobed around edges, pruinose
Color
Whitish-grey to greenish-grey
Reproduction
Apothecia: sometimes present, black disc and margin
Soralia: numerous, green, forming clusters towards the center of the thallus
Isidia: —
Risk of confusion
Distinguished from other crustose lichens by its conspicuous lobes
Substrate
On bark, rock, or artificial substrate
Habitat
Heliophilous and nitrophilous
Sensitivity to air pollution
Resistant to pollution