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.