Life habit: lichenized Thallus: crustose, continuous or rimose-areolate, without elongated lobes; prothallus: present, yellow surface: yellowish orange, without asexual propagules cortex: cellular, 15-28 µm thick; medulla dense, without granules Apothecia: immersed or adnate, 0.2-0.5 mm in diam., lecideine disc: orange, flat, epruinose margin: persistent, flush; thalline margin present, concolorous with thallus; proper margin visible, concolorous with disc parathecium: cellular (paraplectenchymatous); exciple below hypothecium prosoplectenchymatous epihymenium: golden, K+ red, H-, 10%N-, cN-, C- hymenium: hyaline, 50-60 µm tall paraphyses: not swollen or 1-2 tip cells slightly swollen, with few branches; subhymenium hyaline asci: cylindrical, 8-spored ascospores: hyaline, 2 locules, ellipsoid, 8.5-11 x 5.5-7 µm, isthmus 3-4 µm, spore end wall thin Pycnidia: present, ostiole orange Spot tests: apothecial margin K+ red, H-, 10% N-, cN-, C-; thallus K+ red, H-, 10%N-, cN-, C-. Secondary metabolites: unidentified anthraquinones Substrate and ecology: on calcareous rocks or occasionally on non-calcareous rocks World distribution: Caribbean and Central America Sonoran distribution: Sonora and Chihuahua. Notes: Caloplaca baueri is distinctively yellow orange, usually smooth, with immersed apothecia. Occasionally in older thalli it may become rimose areolate. Caloplaca cinnabarina and C. rubelliana have darker orange thalli that are areolate from the beginning. The apothecia on thin thalli of C. baueri are totally immersed but in older and thicker thalli they become more sessile.