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, continuous or rimose-areolate, without elongated lobes; prothallus: absent surface: gray, smooth, without asexual propagules cortex: indistinct, thin, without granules Apothecia: immersed or adnate, 0.2-0.5 mm in diam., lecanorine disc: brown to dark brown to black, flat, epruinose margin: persistent, flush; thalline margin absent; proper margin visible, concolorous with disc parathecium: cellular (paraplectenchymatous) including exciple below hypothecium epihymenium: light brown, K+ violet, H+ violet, 10%N + violet, cN+ violet, C+ violet hymenium: hyaline, 35-60 µm tall paraphyses: 1-2 tip cells slightly swollen, with some branching; subhymenium hyaline asci: cylindrical, 8-spored ascospores: hyaline, 2 locules, ellipsoid, 10-12.5 x 4-5.5 µm, isthmus 3-4 µm, spore end wall thin Pycnidia: not observed Spot tests: apothecial margin K+ violet, H+ violet, 10% N+ violet, cN+ violet, C+ violet; thallus H+ violet, 10%N+ violet, cN+ violet, C+ violet Secondary metabolites: thalloidima green. Substrate and ecology: on non-calcareous rocks World distribution: Europe, North America Sonoran distribution: Arizona, Baja California Sur, western Chihuahua, and Sonora. Notes: Caloplaca conversa characteristically has small spores, small black apothecia, and frequently partly immersed apothecia. The thallus is usually thin and finely areolate.