Thallus: crustose, poorly developed or composed of dispersed warts areoles: ±rounded to irregular in outline, 0.05-0.15(-0.25) mm in diam., moderately to strongly convex, ecorticate but sometimes with a loose unorganised alga-free layer of various hyphae surface: pale yellow or greenish ochre to grayish brown, dull, very rarely slightly glossy, esorediate Apothecia: rounded or irregular, polygonal when crowded, rarely flexuose, single or in small groups, often densely crowded, sessile with a weakly constricted base, 0.40-0.75(-1.20) mm in diam. disc: orange-or red-brown to almost black, rarely pinkish beige, flat to moderately, very rarely strongly convex, dull and with a whitish pruina when wet margin: yellowish or greenish beige to ochre, usually slightly lighter than thallus, weakly to strongly prominent when young, persistent, very rarely excluded with age, smooth or more often slightly knobby, without a parathecial ring amphithecium: present, with an algal layer, laterally 60-120 µm, basally (55-)75-140 µm wide, medulla with short-celled, ±moniliform hyphae with lumina 1-2(-2.5) µm wide, often with brownish granules (soluble in K) at border between medulla and cortex, corticate; cortex: usually slightly thicker and strongly gelatinized near base, with lumina of hyphae 1.5-3(-4) µm wide, 5-20 µm thick parathecium: rarely missing or present and 10-20 µm wide epihymenium: orange- to dark red-brown, often with an olive-green tinge, formed by paraphysis tips, granules (soluble in K) and amorphous pigmentation, 5-15(-25) µm thick hymenium: hyaline or mostly with orange-brown granular patches, 40-60 µm tall; paraphyses: hyaline, often with brown apical cell walls, weakly branched and anastomosing, with lumina basally 1-1.2 µm wide and apically 1.2-2.5 µm wide, sometimes apical gelatinous sheaths 3.5-5 µm wide; subhymenium: hyaline, 20-60(-90) µm thick; hypothecium: hyaline or pale yellowish brown, 10-90 µm thick asci: clavate, 8(16)-spored ascospores: hyaline, simple, often slightly bent or deformed, +narrowly ellipsoid, (6.5-)8.4-12.3(-15) x (3-)3.4-4.7(-5.5) µm Pycnidia: 65-150 µm in diam., semi-immersed to immersed, ±globular, with a pale brown wall conidia: fusiform to bacilliform, sometimes slightly bent, 4-7.5 x 1-1.5 µm Spot tests: thallus K-, C-, KC-, P- Secondary metabolite: isousnic acid. Substrate and ecology: sometimes endosubstratal, mostly on dead wood and conifer bark World distribution: North America and Europe Sonoran distribution: Arizona and southern California above c. 1500 Notes: Lecanora coniferarum is similar but has broader ascospores, a basally thickened excipular cortex, and usnic acid as main lichen substance. For the distinction from L. laxa and L. mughicola see under those species. One collection with 12-16-spored asci and spores of 4.5-6.0 x 4.0-5.0 µm is known.