Thallus: crustose, areolate-subsquamulose to verrucose-areolate, closely attached, sometimes coalescing into a crust which becomes coarsely cracked areoles: rounded, round-angular or sinuate-lobate, concave to slightly convex or undulate, with slightly ascending margins, contiguous to crowded and subimbricate, 0.3-0.8(-1) mm wide, 0.18 upper surface: medium to dark grayish brown, light to dark grayish-yellowish brown, moderate to dark yellowish brown, or yellowish gray, darker parts turning brown to reddish brown when wet, narrowly edged and sometimes mottled with yellowish gray, light gray, or white, dull, epruinose, upper cortex: prosoplectenchymatous, hyaline with a red-brown rim at least in upper c. 30 µm, with conglutinate, mostly anticlinal hyphae 5-10 x 2-3 µm, overall up to 50 µm thick, overlain by a sharply delimited epinecral layer 15-25 µm thick medulla: not developed; algal layer: continuous or interrupted, 50-200 µm thick; algal cells: globose, 8-20 µm in diam. lower cortex: thick, composed of scarcely branched, anticlinal hyphae with transverse septate and thick-walled, externally olive-black, K+ violet lower surface: pale orangish yellow to white, without rhizines, affixed to the substrate by medullary hyphae Apothecia: few to many, dispersed, adnate-sessile to sessile, +circular in outline, 1-1.5 mm in diam. disc: brownish black, plane, soon convex, µmbonate-uneven or at times slightly depressed in center, bare to slightly glaucous-pruinose, dull, scabrid, scarcely changed when wet margin: thalline, concolorous with thallus or white, almost always pruinose at least at first, +level with disc, entire or subentire, thick but becoming thin, c. 0.1 mm wide, +persistent or becoming depressed amphithecium: containing a layer of strong conglutinated paraplectencymatuous cells, up to 200 µm thick at lower parts, without an epinecral layer; algal layer: irregular, up to 100 µm thick parathecium: evident, slightly paler than the disc, paraplectenchymatous, up to 70 µm thick, with conglutinated cells with lumina 2-3 µm in diam. epihymenium: dark red-brown to black, subgranular, not interspersed, 12-15 µm thick hymenium: hyaline below, (55-)70-90(-100) µm tall; paraphyses strongly conglutinate, simple, or forked in upper part, with cells 8-12 x 2-2.5 µm below, with clavate to capitate tips 3.5-6 µm wide; hypothecium: hyaline, up to 100 µm thick asci: oblong-clavate, Bacidia-type, 30-50 x 10-20 µm, 8-spored ascospores: hyaline, 1-septate, not or scarcely constricted at septum, oblong to fusiform-oblong, straight or slightly curved, (16-)18-25(-27) x 4-5 µm, with a very thin halo which is visible in K but becomes inconspicuous, often conglutinate outside the ascus; wall: sometimes fine roughened in appearance, Pycnidia: immersed, inconspicuous, 100-150 µm in diam., ostiole 50-100 µm wide; conidiophores: short celled; conidiogenous cells: elongate 8-12 x 2 µm, branched conidia: filiform, acrogenously formed, arcuate, 14-20(-22) x c. 0.8 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on bare soil or clay (or rarely on rock), often in slight depressions, on S-facing slopes, in mixed oak-chaparral pasture World and Sonoran distribution: southern California at 75-180 m. Notes: In its typical form, Lecania toninioides is easily recognized by its squamulose thallus with pale edges, its long ascospores, and its usual occurrence on soil. However, as seen in some transitional specimens, it can also have a quite different thallus morphology, and can be confused with several other species in the Sonoran region, including L. brunonis and L. subdispersa (see notes under those species).