Life habit: lichenicolous Thallus: crustose, areolate, without elongated lobes; prothallus: absent surface: orange, smooth, isidiate isidia: laminal, cylindrical cortex: cellular, thin Apothecia: rare, adnate, 0.3-0.4 mm in diam., lecanorine disc: orange, flat or slightly concave, epruinose margin: persistent, flush; thalline margin absent; proper margin visible, concolorous with disc parathecium: elongate to oval cells; exciple below hypothecium cellular (paraplectenchymatous) epihymenium: golden, K+ red hymenium: hyaline, 70-75 µm tall paraphyses: 1-2 tip cells slightly swollen, frequently branched; subhymenium hyaline asci: cylindrical, 8-spored ascospores: hyaline, 2 locules, ellipsoid, 12-17 x 6-8 µm, isthmus 1-1.5 µm, spore end wall thin Pycnidia: not observed Spot tests: thallus K+ red Secondary metabolites: unidentified anthraquinones. Substrate and ecology: on non-calcareous rocks World distribution: North America Sonoran distribution: Arizona, Baja California Sur, and western Chihuahua. Notes: Caloplaca wetmorei is a parasitic species with little orange thallus but has abundant fine isidia. It is found at higher elevations and may grow on various host lichens. Caloplaca epiphora has simple to coralloid isidia but it only occurs on bark and wood, is not parasitic, and the spore isthmus is wider.