Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Thallus: crustose, warted-areolate, warts often coalescing to form a rimose crust; prothallus: occasionally present, white, around thallus and between areoles areoles: isodiametric in outline, sometimes irregularly incised or proliferating, 0.10-0.15 mm in diam., moderately to strongly convex, ecorticate but sometimes with a loose unorganised alga-free layer of various hyphae surface: yellowish or greenish beige to gray, dull, occasionally covered with terpenoid crystals, esorediate Apothecia: rounded to flexuose, sometimes tuberculate, single or in groups of 2-3, rarely densely crowded, sessile with a ±constricted base, 0.35-0.70 mm in diam. disc: yellowish beige to orange-brown or ochre, sometimes with an olive tinge, weakly to strongly convex or rarely flat, dull, usually with a fine white pruina, rarely epruinose margin: lacking or rarely present as a weakly prominent rim and soon excluded, without a parathecial ring amphithecium: lacking parathecium: biatorine, hyaline within, outer part with granules (soluble in K) like in the epihymenium, laterally 20-65 µm, basally 20-70 µm wide, with strongly gelatinized, branched, anastomosing, radiating hyphae with narrowly cylindrical lumina 0.7-1(-1.5) µm wide (lumina of apical cells 1-1.5(-2) µm wide) epihymenium: greenish ochre to orange-brown, (coarsely) granular, 5-15 µm thick hymenium: hyaline to pale yellow-brown, 35-50 µm tall; paraphyses: hyaline, weakly branched and anastomosing, with lumina basally 0.7-1 µm wide and apically 1-1.5 µm wide; subhymenium: hyaline, 25-55(-75) µm thick; hypothecium: hyaline, 30-90 µm thick asci: clavate, 8-spored ascospores: hyaline, simple or very rarely 1-septate, narrowly ellipsoid, (7-)9.2-12.1(-13.5) x (3-)3.5-4.4(-5.5) µm Pycnidia: not observed Spot tests: thallus K-, C-, KC-, P- Secondary metabolites: usnic acid, zeorin, arthothelin, ±thiophanic acid, ±4,5-dichloronorlichexanthone (tr.), norlichexanthone (tr.). Substrate and ecology: mostly conifer bark above 1950 m World distribution: North America and Eurasia Sonoran distribution: Arizona, southern California, and Chihuahua. Notes: Lecanora butyracea is very similar but has broader ascospores. Lecanora confusa and related species may resemble L. symmicta, because the apothecial margin is often excluded in older apothecia. Young apothecia of these species are, however, always marginate.