Identification key
Pseudevernia furfuracea
(1) Pseudevernia furfuracea
Description
Thallus
Fruticose, up to 10 cm long, relatively wide strips (up to 5 mm wide), pendulous, with distinct colors on each side

Color
Upper side grayish, underside black
Reproduction
Apothecia: very rarely present, concave, dark brown disc
Soralia: absence
Isidia: generally abundant on the upper side, gray, cylindrical (4)
Risk of confusion
Evernia prunastri has a whitish underside and soralia
Ramalina farinacea has soralia and is the same color on both sides (green)

Ecology
Substrate
On bark, rarely on calcareous rock

Habitat
Rather acidophilic, heliophilic

Occurrence
Common

Sensitivity to air pollution
Particularly sensitive to nitrogen pollution

(2)
(3)
(4) Isidia