Xanthoparmelia stenophylla (Ach.) Ahti & D. Hawksw. chémo protomatrae = Xanthoparmelia protomatrae (Gyel.) Hale

  Thallus foliose in a rosette 5-10 cm in diameter, formed of narrow and elongated lobes, more or less indented, 0.5-3 mm wide, upper surface spotted (lens), without isidia or soralia, grayish white in weather dry, whitish a little glaucous in humid weather, underside with simple rhizines, blackish to brownish in the center of the thallus, lighter towards the margin. Apothecia sessile and even slightly stipitate when mature, concave, brown disc, smooth margin concolorous to the thallus. Ascospores simple, elliptical, hyaline, 7-9 x 4.5-5.5 µm. Common pycnidia. Photobiont: green algae. Cortex: C-, K-, KC- or KC +/- yellow, P-; medulla: C-, K+ brownish, KC-, P+ orange. Heliophilous species growing close to the ground on non-calcareous rocks.

N.B. Taxon considered by French authors as a chemotype of Xanthoparmelia stenophylla s.l..