Lichenologist, 42: 440, 2010. Basionym: Buellia saxorum var. flavescens J. Steiner - Verh. zool.-bot. Ges. Wien, 22: 345, 1907.
Distribution: N - Lig (Senkardser 2010).
Description: Thallus crustose, episubstratic, rimose or rimose-areolate, white to yellowish white, epruinose, usually delimited by a black prothallus. Medulla white, but partly yellowish-inspersed, I+ blue. Apothecia lecideine, black, sessile and constricted at base, 0.2-0.5 mm across, with a flat to convex, epruinose disc, and a thick, raised, persistent proper margin. Epithecium brown, N-; hymenium colourless, not inspersed with oil droplets, 40-70 µm high; hypothecium dark reddish brown. Asci 8-spored, clavate, Bacidia-type. Ascospores 1-septate, brown, ellipsoid, 12-14 x 7-9 µm, Physconia-type, the wall with a median thickening but without lateral thickenings. Photobiont chlorococcoid. Spot tests: K+ yellow, C+ deep yellow, KC+ yellow, P- or P+ faintly yellow. Chemistry: atranorin and placodiolic acid.
Note: a recently-resurrected saxicolous species growing on siliceous rocks at low elevations. For further details see Senkardesler (2010).