Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, immersed or reduced to scattered granules or areoles on a black prothallus (often absent) areoles: irregular in outline or ±isodiametric, 0.1-0.2 mm in diam., weakly convex to irregularly wrinkled, ecorticate surface: yellowish or greenish ochre or yellow-brown, glossy, esorediate Apothecia: sessile to constricted below, often clustered, round to irregular, 0.5-1.8 mm in diam. disc: pale yellow to pale yellow-brown, gelatinous epruinose margin: indistinct, without a parathecial ring amphithecium: present, with sparse algae, lacking crystals, laterally 30-70 µm wide, basally up to 110 µm wide, corticate; cortex: gelatinised, 15-30 µm wide parathecium: hyaline, 25-50 µm wide epihymenium: yellowish brown, with granular crystals dissolving in K hymenium: hyaline, clear or inspersed; paraphyses: weakly branched and anastomosing, slightly thickened (up to 2.5 µm wide) apically; subhymenium: hyaline, 15-20 µm thick; hypothecium: pale yellow, somewhat indistinct asci: clavate, 8-spored ascospores: hyaline, simple, narrowly ellipsoid, 8-14 x 2.5-4.5 µm Pycnidia: not seen Spot tests: thallus K-, C-, KC-, P- Secondary metabolites: isorangiformic acid, usnic acid and zeorin. Substrate and ecology: on hard siliceous rocks in alpine habitats World distribution: Europe, North America and New Zealand, probably cosmopolitan but mostly overlooked since it's very similar to L. polytropa Sonoran distribution: southern California. Notes: Lecanora stenotropa is morphologically indistinguishable from morphotypes of L. polytropa lacking a conspicuous thallus, but can be separated by the ascospore shape, being narrowly ellipsoid in L. stenotropa and broadly ellipsoid in L. polytropa and the different fatty acids.