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

Life habit: lichenized Thallus: crustose, areolate, without elongated lobes; prothallus: present, black surface: yellowish orange, smooth or verruculose, without asexual propagules cortex: cellular, thickness moderate, 25-30 µm, granules absent, without granules Apothecia: present, stipitate, 0.5-2 mm, lecanorine disc: orange, flat margin: persistent, slightly raised; thalline margin present, concolorous with thallus; proper margin not visible parathecium: irregular hyphae; exciple below hypothecium amorphous epihymenium: golden, K+ red, H-, 10%N-, cN-, C- hymenium: hyaline, 70-95 µm tall paraphyses: 1-2 tip cells slightly swollen, with few branches; subhymenium hyaline asci: cylindrical, 8-spored ascospores: hyaline, 2 locules, ellipsoid, 12.5-14 x 5.5-7 µm, isthmus 4-5.5 µm, spore end wall thin Pycnidia: present, mostly immersed, 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 bark World distribution: southwestern North America and Mexico Sonoran distribution: southern California, Baja California, and Baja California Sur. Notes: Caloplaca stipitata is a distinctive species mainly characterized by the stipitate apothecia with a basally expanding apothecial cortex. The thallus is usually very yellowish-orange with areoles growing vertically and expanding . The thalline parts of this species often develop yellow crystals (insoluble in water and K) on the surface after 8-10 years in the herbarium. Caloplaca flavorubescens is similar but has sessile apothecia with uniformly thin cortex and the thallus is initially immersed in the bark. Caloplaca stipitata has also been confused with C. californica but the latter species is a more northern maritime species occurring on wood with very crowded non-stipitate apothecia, thinner apothecial margins, and slightly narrower spores with slightly narrower isthmus.