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: leprose, continuous, without elongated lobes; prothallus: absent surface: brownish orange, sorediate soredia: fine, brownish orange, leprose, not in well defined soralia cortex: absent; medulla prosoplectenchymatous Apothecia: absent Pycnidia: not observed Spot tests: thallus K+ red, H-, 10%N-, cN-, C-; medulla IKI- Secondary metabolites: unidentified anthraquinones. Substrate and ecology: on bryophytes and calcareous rocks World distribution: Europe and North America Sonoran distribution: Arizona. Notes: Caloplaca chrysodeta is entirely leprose with no corticate areas. The thallus is often somewhat thick with a white cottony medulla. Caloplaca citrina has been confused with C. chrysodeta but C. citrina usually has some cortex and much thicker thallus with slightly lobed margins. In C. chrysodeta the color of the soredia is darker brownish orange instead of distinctly yellow as in C. citrina. The ecology is also distinct with C. citrina occurring in exposed places and C. chrysodeta in moist, shady places, such as limestone sinkholes and cave entrances.
Taxonomic note. Ahti (2015), pointing out that Vainio already published the basionym of this species in 1921, only recently validated the combination L. chrysodeta first proposed, but not validly published by Laundon (1974).
Description. Thallus leprose, entirely composed of coarse, deep yellow to orange granules, occasionally in parts ± brownish orange or grayish yellow; individual granules without protruding hyphae, pseudocorticate, (30–)27–44(–45) μm in diam., either dispersed and isolated, or, when well developed, closely aggregating into a thick crust that secondarily breaks apart and then looks ‘areolate’; not delimited by a prothallus, hypothallus absent. Apothecia unknown.
Chemistry. Thallus P–, K+ purple, C–, KC± purplish (fading), UV– (dull); with a large proportion of parietin and smaller proportions of teloschistin, fallacinal, parietinic acid and emodin (chemosyndrome A sensu Søchting 1997).
Ecology and distribution. Cosmopolitan; in Galapagos, known from a single specimen only, collected at a shaded, sheltered, W-exposed overhang, in the high-altitude dry zone of Volcán Darwin (Isabela).
Notes. Bungartz et al. (2013) did not include the species in their key to leprose and leproid lichens from the Galapagos. At the time, the only known record was still considered preliminary. DNA extraction from the single known specimen unfortunately failed, but its morphology and secondary chemistry agree well with L. chrysodeta, which is presently the only known leprose ‘Caloplaca’ from the Americas.