Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, ± firmly appressed, up to 10 cm in diam. but usually much smaller (3-4 cm) lobes: flat, rarely slightly convex or concave, 0.4-0.8 mm wide upper surface: light yellowish brown, gray or almost white; pseudocyphellae: sparse, usually restricted to the peripheral parts of the lobes, sometimes reticulately confluent; pruina: patchy, often glistening soredia: always present, granular, rarely farinose, initially in marginal, fissural, then in laminal, orbicular soralia; isidia and polysidiangia lacking medulla: white throughout lower surface: black in center, paler towards lobe tips; rhizines: ± dense, blackish, furcately divided Apothecia: cocoes-type, rare, laminal, 0.4-1.4 mm wide; disc: black, not pruinose internal stipe: distinct, upper part brownish-red (rarely white: P. cocoes var. pallida - not yet known from the Sonoran region), lower part white ascospores: one-septate, brown, 15-18 x 6-7 µm Pycnidia: immersed conidia: bacilliform, 3-4 x 1 µm Spot tests: upper cortex K-, C-, KC-, P-; medulla upper and lower part K-, C-, KC-, P-; internal stipe upper part K+ red, C-, KC+ purple, P-; lower part K-, C-, KC-, P- Secondary metabolites: upper cortex with lichexanthone, medulla with a few terpenes in low concentration. Substrate and ecology: on bark and wood near sea sides, rarely on acidic rock or in montane areas World distribution: pantropical with scattered collections from the subtropics and insular Laurimacaronesia Sonoran distribution: southern Arizona and Baja California Sur.