Thallus lemon-yellow to orange, at first of small areolae 0.1—0.2 mm, the areolae soon verruculose-granulose with tiny granules, but sometimes environmental forces strip the granules and leave only a yellowish white thallus remnant. Apothecia unknown.

This species grows over moss and humus in well-manured sites. It was described from eastern Greenland, and several west Greenland localities were added by Hansen, Poelt, & S0chting (1987). It has been reported from Colorado by Anderson (1974) and should be sought in the American Arctic.

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 to subsquamulose, margin abrupt at edge, without elongated lobes; prothallus: absent surface: yellowish orange, smooth, without asexual propagules Apothecia: adnate, 0.4-1 mm in diam., lecanorine disc: dark reddish orange, flat, epruinose margin: persistent, flush; thalline margin present, concolorous with thallus; proper margin visible, concolorous with disc parathecium: irregular hyphae; exciple below hypothecium cellular (paraplectenchymatous) hymenium: hyaline, 60-70 µm tall paraphyses: 1-2 tip cells swollen, frequently branched; subhymenium hyaline asci: cylindrical, 8-spored ascospores: hyaline, 2 locules, ellipsoid, (11-)12.5-14(-15.5) x 5.5-7 µm, isthmus 1.5-3(3.5) µm, spore end wall thin Pycnidia: not observed Spot tests: apothecial margin K+ red; thallus K+ red Secondary metabolites: parietin and emodin. Substrate and ecology: on bark, especially Juniperus World distribution: southwestern North America Sonoran distribution: Arizona at intermediate elevations. Notes: Caloplaca arizonica has a yellow-orange areolate thallus and resembles C. flavovirescens but that species is on rock. The apothecia of C. arizonica are dark red-brown without a thalline margin.