Candelariella reflexa (Nyl.) Lettau

    Thallus ± crustose, made of granules, 0.1-0.2 mm diam., greenish to yellow-green in the shade and yellow when lit, made also of minute squamules, 0.5-1 mm, covered often by abundant bright yellow soredia, tending to form a leprose and farinose crust. Apothecia very rare, 0.5-1 mm diam., disc plane, yellow, concolourous margin, not sorediate. 8-spore asci. Ascospores simple, ellipsoid, bi-guttulate, 10-17 x 4,5-5,5 µm. Photobiont : chloroccocoide. C-, K-, KC-, Pd-. Rather common, including in cities, on nutrient-rich barks of deciduous trees (notably Salix, Populus, etc.) towards the base of trunks (where dogs usually urinate).

N.B. Candelariella xanthostigma is a very close species but its thallus displays only granules and no soredia and whose asci are 16-32 spores

N.B. Also similar to some Caloplaca citrina agg. taxa, but easily determined by the K+ purple reaction. Candelaria concolor K-, is often also confused, but grows at higher levels on trunks, and has much larger and divided squamules; Xanthoria candelaria is K+ purple.*