Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Life habit: lichenized Thallus: crustose to subsquamulose or placodioid or umbilicate foliose upper surface: orange yellow to brownish yellow, smooth, shiny epicortex: thin to thick, gelatinuous, hyaline upper cortex: pseudoparenchymatous medulla: white, compact and thick or indistinct photobiont: primary one a chlorococcoid green alga confined to a distinct algal layer or evenly dispersed throughout the thallus, secondary photobiont absent lower cortex: similar to the upper cortex lower surface: pale yellow Ascomata: apothecial, lecanorine disc: rounded, ±flat margin: persistent, concolorous with the thallus exciple: thin and indistinct to well developed, not visible from the outside asci: clavate, Candelaria-type, 32+-spored ascospores: hyaline, simple or sometimes with a thin septum, narrowly ellipsoid, straight, with one to many oil-drops Conidiomata: pycnidial, immersed, darker yellow than the thallus conidia: hyaline, ellipsoid Secondary metabolites: pulvinic acid derivatives, not investigated here Geography: South America and SW North America Substrate: on rocks. Notes: Placomaronea was previously unknown from North America. The genus is characterized mainly by the structures of the cortical layers. In sections the cortex appear thick and well defined, and the pigments are characteristically arranged as "hoods" on the outermost cortical cells. Uppermost there is a gelatinuous epicortex causing the smooth shiny appearance of the thallus. The species is keyed with Candelariella.