Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, verrucose to subsquamulose, slightly effigurate at the margins, bullate, ecorticate; prothallus: not visible surface: yellowish white to yellowish gray, glossy, epruinose, with an indistinct margin, esorediate Apothecia: immersed when immature, becoming sessile to slightly constricted at the base, 0.4-1.2 mm in diam., lecanorine disc: pale to dark red-brown, epruinose margin: concolorous with the thallus, thin, entire, ±verrucose to crenulate, without a parathecial ring amphithecium: present, with numerous algal cells, with large crystals insoluble in K, corticate; cortex: hyaline, ±gelatinous, inspersed, 15-25 µm thick laterally and 20-30 µm thick basally parathecium: hyaline, without or with very few small crystals, 10-15 µm thick epihymenium: reddish brown, K-, with numerous small crystals soluble in K, 10-15 µm thick hymenium: hyaline, clear., inspersed with oil droplets; paraphyses: sparingly branched and thickened apically; subhymenium: hyaline, 15-20 µm thick; hypothecium: hyaline, without oil droplets asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid to subglobose, (3.5-)8-13 x 5-8(-13.5) µm Pycnidia: not seen Spot test: thallus and apothecial margin K+ yellow, C-, KC-, P+ pale orange Secondary metabolites: atranorin (major) and chloroatranorin (minor). Substrate and ecology: on exposed siliceous rocks at lowland elevation World distribution: subcosmopolitan, known from Africa, Australasia, North and South America Sonoran distribution: Baja California Sur and Sonora. Notes: Lecanora galactiniza can be recognized by relatively small apothecia, a well developed, subsquamulose thallus and a granulose epihymenium. Similar species include L. subimmergens and L. pseudistera. These are, however, distinguished by an egranulose epihymenium and a different chemistry. In addition, the thallus of L. pseudistera is usually much more robust than the thallus of L. galactiniza. This is the first record of this species for North America.
Type: South Africa. Western Cape: Cape of Good Hope, exact locality unknown, original label data: “Cap B. Spei”, 1874, Eaton, A.E. s.n. [(H-Nyl 27914–lectotype selected by Guderley (1999)].
Description. Thallus saxicolous, moderately thickened, verruculose areolate to bullate areolate or of distinctly subsquamulose areoles with convex edges, especially along the thallus margin; surface white to pale gray, rarely ±brownish gray, smooth, ±shiny, epruinose, lacking soredia; prothallus absent. Apothecia numerous, often densely aggregated, circular in outline, 0.3–0.6(–0.9) mm in diam., adnate to sessile, often crowded, distinctly lecanorine with a smooth to coarsely verrucose-crenulate, epruinose margin, concolorous with the thallus; disc plane to slightly convex, yellowish to greenish orange or intensely reddish brown, epruinose; hymenium hyaline, not inspersed, epihymenium with a persistent, insoluble yellowish reddish brown pigment (arnoldiana-brown: K+ dull brown, HCl+ reddish brown, N−) and crystals that dissolve in K (pulicaris-type); proper exciple thin, indistinct, with few crystals; thalline exciple thick, ±corticate, with large crystals insoluble in K (pulicaris-type); hypothecium hyaline; ascospores 8/ascus, simple, narrowly to broadly ellipsoid, (6.9−)9.3−12.2(−13.9) × (4.0−)5.0−6.3(−6.9) μm (n = 45). Pycnidia not seen.
Chemistry. Thallus cortex including apothecial margin P+ yellow, C−, KC−, K+ yellow; with atranorin [major], SV-1 [minor; derived from the photobiont and of no taxonomic significance]; [specimens analyzed with TLC: Aptroot, A. 65267 (CDS 31853), Bungartz, F. 6956 (CDS 36460), 8434 (CDS 41080); Jaramillo, P. 2890 (CDS 38810)].
Ecology and distribution. Almost cosmopolitan, with a preference for Mediterranean to subtropical climates, relatively few reports from South America (Guderley 1999), new to Ecuador and the Galapagos; a moderately common species from the dry to the high altitude dry zone, in semi-shaded to exposed, often ±sheltered habitats close to the ground.
Notes.Lecanora galactiniza could be mistaken for the more common L. sulfurescens, but the apothecia of L. galactiniza are generally larger and typically have a deeper reddish brown disc, rather than being orange or pale yellow as in L. sulfurescens. With their strongly convex, granular to even subsquamulose areoles the thalli of L. galactiniza are morphologically quite different from L. sulfurescens, which typically has a smooth, continuous surface. Immature specimens of L. sulfurescens develop as discontinuous, much more isolated areoles on a spidery prothallus and on particularly grainy rock surfaces the thalli may become unusually granular. These thalli can then easily be confused with L. galactiniza. Both species contain atranorin but L. sulfurescens also contains gangaleoidin. Morphologically thalli of L. galactiniza closely resemble those of L. kalbii, but that species is pale yellow colored, the pigmentation caused by the presence of xanthones (thiophanic acid [major] and 3-Omethylthiophanic acid).