Melanelixia glabra (Schaer.) Blanco & al.
Parmelia glabra (Schaer.) Essl.
Melanelia glabra (Schaer.) Nyl.
Thallus foliose, rosette-shaped, 5-12 cm diam. rather tightly attached to the substratum, composed of lobes, 2-6 mm wide, apices round, upper surface covered with minute hyaline bristles, more or less scattered, without isidia and soralia but sometimes with pseudocyphellae, more or less aligned, brown-olive, green-olive when dry, turning more greenish when moist, lower surface blackish towards the center and brown towards margins with simple concolourous rhizines. Apothecia usually abundant, sessile and cup-shaped, 0.3-10 mm diam., disc concave then plane, brown-red, thalline exciple crenulate to fluted, presence when young of the same hyaline bristles as on the thallus. Ascii clavate, 8-spored, 50-60 x 20-25 µm according to our measures. Ascospores colourless, simple, broadly ellipsoid, 11-15 x 6-8 µm according to literature, 10-13 x 6-9 µm according to our measures. Cortex: C-, K-, KC-, Pd- ; medulla: C+ pink-red, KC+ red, K-, Pd-. Montane (600-1000 m) and mediterranean species, on bark of deciduous trees, in low density woodlands. N.B. This species has not (yet) been found in our prospection area and is presented here owing to its similarities with Pleurosticta acetabulum of which lobes are larger, greener and dotted towards the margins with brown-black pynidia, medulla K+ red, Pd+ orange.*