Thallus: crustose, continuous or verrucose-areolate; prothallus: not visible areoles: flat or verruculose, thin or thick, opaque, ecorticate surface: yellowish white to yellowish gray or whitish gray to gray, smooth or rough, epruinose, with an indistinct margin, esorediate Apothecia: sessile, 0.4-1 mm in diam., lecanorine disc: red-brown or orange-brown, plane, epruinose margin: concolorous with thallus, thin or thick, persistent or becoming excluded, even or prominent, entire or flexuose, smooth, entire or verrucose or verruculose, without a parathecial ring amphithecium: present, with numerous algal cells, with large crystals insoluble in K, corticate; cortex: hyaline, distinct, basally thickened, gelatinous or interspersed, (15-)20-25(-30) µm thick laterally, 25-50 µm thick basally parathecium: hyaline, lacking crystals epihymenium: with crystals dissolving in K, red-brown to orange-brown, with pigment dissolving in K hymenium: hyaline, clear; paraphyses: slightly thickened apically, not pigmented; subhymenium: hyaline, 15-20 µm thick; hypothecium: hyaline, without oil droplets asci: clavate, 8-spored ascospores: hyaline, simple, broadly ellipsoid, (9-)12-14(-14.5) x (5-)5.5-7(-8.5) µm; wall: less than 1 µm thick or more than 1 µm thick Pycnidia: not seen Spot tests: K+ yellow, C-, KC-, P- or P+ pale yellow Secondary metabolites: atranorin (major), chloroatranorin (minor), roccellic acid (major or absent). Substrate and ecology: on bark of deciduous trees, such as Acer, Populus, or Quercus World distribution: western Europe and North America Sonoran distribution: Arizona and southern California. Notes: Lecanora hybocarpa is similar to L. chlarotera, L. circumborealis and L. pulicaris. From L. circumborealis it differs in having a uniform cortex, while L. chlarotera contains the gangaleoidin chemosyndrome and has a different epihymenial type. Lecanora pulicaris usually contains the fumarprotocetraric acid chemosyndrome. Chemotypes of L. pulicaris lacking these depsidones can be distinguished by broader ascospores and a brown epihymenium.