Thallus: crustose, rimose-areolate areoles: irregular in outline, 0.15-0.30 mm in diam., weakly convex, ecorticate but sometimes with a loose unorganised alga-free layer of various hyphae surface: beige to ochre, somewhat glossy, esorediate Apothecia: irregular, single or in groups up to 3, sessile with a constricted base, 0.55-0.85 mm in diam. disc: ochre, flat, dull, white pruinose margin: interior part close to disc dull and pale gray, outer part glossy and of same color as thallus, very prominent when young, persistent, without a parathecial ring amphithecium: present, with an algal layer, laterally c. 100 µm thick, basally c. 120 µm wide, medulla with irregularly entangled, short-celled hyphae with lumina c. 1 µm wide, corticate; cortex: lacking above, c. 100 µm wide near base, with small, brownish granules (soluble in K) close to hymenium, composed of strongly gelatinized, anticlinally arranged hyphae with lumina 1.5-2.5 µm wide epihymenium: greenish ochre, finely granular (soluble in K), c. 10 µm thick, hymenium: hyaline, c. 50 µm tall; paraphyses: simple or weakly branched and anastomosing, with lumina basally 1.2-1.5 µm wide and apically 1.5-2 µm wide; subhymenium: hyaline, c. 60 µm thick; hypothecium: pale yellow, c. 30 µm thick asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, 10.5-12.5 x 5-5.5 µm Pycnidia: not observed Spot tests: thallus K-, C-, KC-, P+ yellow Secondary metabolites: usnic acid, psoromic acid (not tested in North American material). Substrate and ecology: wood near sea level World distribution: North America Sonoran distribution: Only known from Santa Catalina Island, California Notes: Although the name has often been used in the literature, the occurrence of the species in the area is dubious (Printzen 2001). Lecanora varia is easily recognized on account of its apothecial margin with a dull zone bordering the apothecial disc surrounded by a more or less glossy outer zone. Lecanora laxa lacks psoromic acid and reacts P-. Lecanora densa is chemically identical, but has smaller apothecia, a distinctive ash gray hypothallus, a thinner marginal cortex and is only known from higher elevations in eastern parts of the study area.