Parmeliopsis hyperopta (Ach.) Arnold

     Foliose thallus strongly appressed to its substrate, arranged in a rosette 3-8 cm in diameter, formed of radiating lobes with rounded, slightly incised ends, upper surface smooth, pale gray, ash gray, covered with more or less globose soredia that can form a thick crust, whitish, pale gray... lower surface blackish with blackish rhizines. Apothecia very rare, lecanorine, sessile, reddish-brown disc, margin more or less sorediate. Spores simple, hyaline, reniform or crescent-shaped, 8-15 x 2-4 µm. Photobiont: chlorococcoid alga. Cortex: K+ pale yellow, C-, KC-, P-; Medulla: K-, C-, KC-, P-, UV+ white. A montane and boreal species growing on the acidic bark of conifers, more rarely on dead wood.

Cf.:

_ Parmeliopsis ambigua, sometimes associated but much yellower.

_ Parmeliopsis capitata with soredia at the tips of the lobes.

_ Imshaugia aleurites, which is isidiate and P+ red.