Thallus: crustose, continuous or rimose-areolate or verrucose-areolate or dispersed-areolate; prothallus: not visible, or white; areoles: flat or verrucose or verruculose, thin, opaque, ecorticate surface: yellowish white to yellowish gray or pale green to greenish white, smooth or rough, epruinose, with an indistinct margin or arachnoid, sorediate soredia: granulose, (30-)40-45(-50) µm in diam, in confluent, pale yellow to yellowish gray or greenish white to yellowish green soralia 0.2-1(-1.4) mm in diam. Apothecia: sessile, 0.5-1.3 mm in diam, lecanorine disc: red-brown or orange-brown, plane, epruinose margin: concolorous with thallus, thin, persistent, even or prominent, entire or flexuose, smooth, entire or verrucose or verruculose or sorediate, without a parathecial ring amphithecium: present, with numerous algal cells, with large crystals insoluble in K, corticate; cortex: indistinct, basally not thickened, interspersed, hyaline, (15-)20-20(25) µm thick laterally, (15-)20-20(-25) µm thick basally parathecium: hyaline, containing crystals insoluble in K epihymenium: red-brown to orange-brown, with pigment not dissolving in K, without crystals hymenium: hyaline, clear; paraphyses: slightly thickened (up to 2.5 µm wide) or capitate apically, red-brown to orange-brown ; subhymenium: hyaline, 15-20 µm thick; hypothecium: hyaline, without oil droplets asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid or broadly ellipsoid, (10-)10.515(-15.5) x (6.5-)7.5-10.5(-11) µm; wall: less than 1 µm thick Pycnidia: not seen Spot tests: K+ yellow, C-, KC-, P- or P+ pale yellow Secondary metabolites: atranorin (major), chloroatranorin (minor), usnic acid (major), and zeorin (major). Substrate and ecology: in deeply shaded habitats on siliceous rocks in montane areas World distribution: North America Sonoran distribution: Arizona, Baja California Sur, Chihuahua, and Sonora. Notes: Lecanora brodoana is characterized by the presence of usnic acid in addition to atranorin, the presence of soarlia, the granulose epihymenium, and the clear, red-brown epihymenium. It is hardly confused with any other saxicolous Lecanora species in the area, except sorediate forms of L. campestris that are readily distinguished by the amphithecium filled with small amphithecial crystals and the absence of usnic acid.