Parmelina pastillifera (Harm.) Hale
Parmelia pastillifera (Harm.) R. Schubert & Klem.
Thallus foliose, rosette-forming, 5-12 cm diam., lobes 3-8 mm wide, margin rounded and roughly crenulate, with a few short cilia, upper surface more or less glossy, pale grey-bluish, pale grey, covered, notably towards the center, by isidia, laminal, flattened, bud-shaped, leaving a white scar after falling, lower surface dark brown to blackish, with simple rhizines. Apothecia unknown in our prospection area, but elsewhere reported as 3-7 mm diam., disc brown-red, exciple shortly rhizinate below. Ascospores broadly ovoid, simple, colourless, 9-10 x 6-9 µm. Cortex: K+ yellow, medulla: C- carmine, K-, KC+ red, Pd-. On bark of trees in humid areas, very seldom on rocks. See Parmelina tiliacea which is rather easy to confuse notably when young, with small isidia pile-forming and clustered towards the center. See also Parmelina quercina with apothecia. N.B. This species is sometimes considered by some authors as an isidiate morph of Parmelina carporrhizans.*