Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.

Life habit: lichenicolous, on discs of Lecanora species (of the L. dispersa-group) Thallus: inapparent photobiont: absent Ascomata: ± round, immersed to erumpent, 0.12-0.4 µm wide disc: black, ±convex epihymenium: pale brown to dark olivacous brown, 8-15 µm thick, with hyphal tips up to 2.5 µm thick and granular pigments hymenium: hyaline, 30-35 µm tall; subhymenium: pale brown, 30-40 µm thick asci: clavate, 25-30 x 18-22 µm, 8-spored, without a distinct stipe ascospores: persistently hyaline, 1-septate (slightly incised at septum), obovate, 10-12 x 3.5-5 µm, lacking an epispore Pycnidia: 40-50 µm wide conidia: not seen Chemical reactions: ascomatal gels I+ red, KI+ blue, with minute KI+ blue ring-structure in the tholus. Substrate and ecology: see the host species World distribution: see host species Sonoran distribution: Arizona (Cononino Co). Notes: Arthonia lecanorina is widespread and common, but it is probably overlooked. The similar Arthonia apotheciorum differs by having thick-walled ascogenous hyphae and by its occurrence on Lecanora varia (Grube and Matzer 1997).