Thallus: crustose, warted-areolate to rimose areoles: moderately to strongly convex, sometimes irregularly wrinkled, 0.15-0.35(-0.50) mm in diam., ecorticate but sometimes with a loose unorganised alga-free layer of various hyphae surface: greenish yellow to ochre or brownish gray, dull, esorediate Apothecia: rounded or slightly irregular in outline, rarely flexuose, single or in groups, sessile with a constricted base, 0.5-0.9(-1.5) mm in diam. disc: orange- or red-brown to almost black, flat to weakly convex, finely white or pale blue pruinose, dull margin: prominent in young apothecia, persistent though usually more flat in older apothecia, yellowish beige, dull, weakly wrinkled or knobby, without a parathecial ring amphithecium: present, with an algal layer, laterally 90-100 Ám wide, basally 100-125(-210) Ám wide, medulla with irregularly entangled, short-celled hyphae with lumina 1-2 Ám wide, corticate; cortex: 5-10 Ám above, 20-35 Ám below, composed of strongly gelatinized anti-clinally arranged hyphae with 1.5-3(-3.5) Ám wide lumina epihymenium: orange- to red-brown, granular (soluble in K) 5-15 Ám thick hymenium: hyaline to pale yellow, often with orange-brown to ochre, granular stripes, 50-60 Ám tall; paraphyses: simple or apically weakly branched and anastomosing, with 0.7-1 Ám, apically 1.2-2(-2.5) Ám wide lumina; apical cells: often with brown walls; subhymenium: hyaline, 20-60 Ám thick; hypothecium: hyaline, 45-100 Ám thick asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, (9-)9.8-11.6(-13) x (4-)4.9-5.6(-6) Ám Pycnidia: not observed Spot tests: thallus K-, C-, KC-, P- Secondary metabolites: ▒isousnic acid (missing in 4 coll.), ▒usnic acid (missing in 1 coll.). Substrate and ecology: sometimes endosubstratal, on wood or old bark of conifers and Quercus World distribution: southwestern North America Sonoran distribution: Arizona, southern California and Baja California above 1250 m in California and 2000 m in the eastern part of the area. Notes: Lecanora coniferarum differs from L. saligna by chemistry, broader and more regularly ellipsoid ascospores and an apothecial margin with a distinctly broadened basal cortex. Lecanora laxa can be distinguished by shorter ascospores and a strongly constricted apothecial base.