Blastenia xerothermica Vondrak, Arup & I.V. Frolov Cf.

    Thin crustose thallus, whitish, grayish, yellowish and even pale brownish in very dry weather. Apothecia usually numerous, 0.3-0.5 mm in diameter, flat disc, orange-brown, rusty, orange, slightly lighter edge. Spores polarilocular, elliptical, hyaline, (10) 12-15 x 4-5 (6) µm with a thickening of 4-5 µm. Branched paraphyses with an apex of 3 µm. Pycnidia appearing as black spots on the thallus. Thallus: C-, K-, KC-, P-. Apothecia: K+ red. Mediterranean species from dry and hot areas growing on the bark of the branches of Mediterranean maquis shrubs.

N.B. Species formerly confused with Blastenia ferruginea but in the latter species the pycnidia appear in the form of red dots.

_ Not distinguishable without DNA analysis from Blastenia hungarica but the latter species is more continental or mountainous and not Mediterranean (?).