Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Thallus: crustose, well-developed, tightly adherent, verrucose-areolate to subsquamulose or dispersed-verrucose; prothallus: when present blackish brown to black areoles: flattened, contiguous or scattered, with a crenulate (jigsaw puzzle-like) margin, slightly lobate surface: gray-green or yellow-green, smooth or finely wrinkled, epruinose, esorediate cortex: with abundant dead algal cells; upper part with hyaline coarse granules insoluble in K medulla: dense, with thick-walled hyphae, without hyphal bundles; algal layer: algae scattered Apothecia: pseudolecanorine to biatorine, (0.4-)0.8-1(-1.5) µm in diam., immersed or sessile, not constricted at base, 1-2 per areole disc: flat to slightly concave or convex, blackish green or greenish brown, epruinose or slightly gray-pruinose margin: prominent to thin or disappearing, at first entire and slightly raised but becoming flexuous, without a parathecial ring amphithecium: present, with a densely packed continuous algal layer extending below the hypothecium, medulla densely interwoven and lacking crystals, corticate; cortex: hyaline, indistinctly delimited, with dense, parallel, anticlinal, swollen hyphae, without dead algal cells, inspersed with dark brown granules (soluble in K), c. 10 µm thick laterally and basally parathecium: hyaline, lacking crystals; subhymenium and hypothecium: hyaline epihymenium: green-brown or brown, c. 10 µm high, inspersed numerous small crystals (pol+), pigmentation and crystals soluble in K hymenium: hyaline, 60-70 µm; paraphyses: simple or sparsely branched; apices: slightly swollen, up to 2.5 µm wide; subhymenium: hyaline, 15-20 µm thick; hypothecium: hyaline asci: oblong-clavate, 8-spored ascospores: hyaline, simple, (8-)10-13(-15) x (4.5-)5-7 µm, oblong to oblong-ellipsoid Pycnidia: immersed conidia: arc-like, 23-25 x 0.5-1 Spot tests: thallus and apothecial margin K- or + pale yellow, C-, KC-, P-; cortex KC+ yellow; medulla KC- Secondary metabolites: usnic acid and zeorin. Substrate and ecology: on siliceous rocks, more rarely on wood World distribution: holarctic-montane, boreal-arctic, arctic and high montane areas of Europe and North America Sonoran distribution: upper montane of Arizona and California. Notes: Lecanora intricata is similar to L. polytropa but with a more extensive yellowish thallus and semi-immersed apothecia with greenish brown to almost black discs. See Eigler (1969) for more details on this species.