Thompson, J., 1997. American Arctic Lichens: The Microlichens.
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.
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.