Kuettlingeria albolutescens (Nyl.) V. Frolov, Vondrák & Arup =Caloplaca albolutescens (Nyl.) H. Olivier

    Thallus crustose, granular and powdery, seldom rugose or fissural, margin indistinct and not lobate, whitish, grey-whitish, pale grey, grey soredia scattered. Apothecia often numerous and scattered throughout the thallus, immersed at first then sessile and sometimes narrowed towards the base, 0,5-1 mm diam, disc flat, orange, brown-orange, pale brown-orange, margin concolourous, persistent or pale, often like duplicate by thallus extension, giving a white external colour similar to Lecanora apothecia. Ascospores ellipsoid, polarilocular, septum up to 1/4 -1/5 of the length of the ascospore, 14-18 x 8-10 µm. Photobiont : trebouxioide. Thallus : K-, but K+ violet in places on soredia, apothecia K+ purple. On weakly acidic stones of walls or mortar bleaching, rather common on chapel walls.

N.B. This species is sometimes very difficult to distinguish from highly fertile morphs of  Caloplaca teicholyta (similar ascospores according to literature) but the latter has less sessile apothecia and a thallus with placodioid margin and definite marginal lobules, scattered with soredia; intermediate forms can be found.