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DescriptionThallus: verrucose-areolate, or corrugate and with large cracks, 2.5-4 cm in diam., (0.2-)0.3-1(-5) mm thick; areoles: angular to rounded or irregular, flat to convex, contiguous, (0.2-)0.4-1.2mm in diam., or fused into larger thallus fragments with corrugated surface, up to 4 mm in diam., separated by large cracks; prothallus: indistinct or thin, at the thallus edge, black, sometimes fimbriate, 0.1-0.5(-1) mm wide; surface: brown to gray-brown, often with gray pruina in parts of the areole; brown areas usually shiny, gray areas dull; upper cortex: 15-30 µm thick, uppermost part brown, 7-10(-15) µm thick, with cells 5-7 µm in diam.; cortex covered with an epinecral layer 2-8 µm thick; photobiont: chlorococcoid, cells ±round, 5-18 µm in diam; Apothecia: aspicilioid, rather common, (0.1-)0.3-1.1(-1.7) mm in diam., 1-2(-3) per areole, round or sometimes angular; disc: black, without pruina or rarely with thin white pruina, concave to plane or rarely convex (larger apothecia); thalline margin: ±elevated, often thick and prominent in larger apothecia, concolorous with thallus; exciple: 20-30(-40) µm wide, I-; uppermost cells brown, ±globose, 4-6 µm in diam.; epihymenium: green to olive or olive-brown, rarely brown, without or with a few crystals, N+ green to blue-green, K+ brown; hymenium: hyaline, I+ persistently blue, (120-)140-200(-250) µm tall; paraphyses: moniliform, rarely submoniliform, with (2-)3-5(-6) upper cells ±globose, 4-5 µm wide, in lower part 1.5-2 µm wide, slightly branched and anastomosing; subhymenium and hypothecium: pale, I+ persistently blue (rarely some parts I-), together 50-70(-90) µm thick; asci: clavate, (65-)80-120 x 17-30 µm, 8-spored; ascospores: hyaline, simple, ellipsoid, (15-)18-24 x (9-)11-14 µm; Pycnidia: rare to rather common, 1(-3) per areole, immersed, 120-250 µm in diam., with a black, punctiform ostiole, 50-80 µm in diam; conidia: filiform, straight or slightly curved, 11-18(-27) x 0.6-0.8(-1) µm; Spot tests: cortex and medulla I-, K+ yellow or slowly turning orange, C-; Secondary metabolites: substictic acid.; Substrate and ecology: on siliceous rock in mountain areas; World and Sonoran distribution: Los Angeles and San Diego Counties in California, at 900-1975 m.; Notes: Aspicilia anglica is characterized by a rather thick, brown to gray-brown, verrucose-areolate to corrugate and cracked thallus, often with gray pruina in parts of the areoles, rather large apothecia, a ±elevated thalline margin, which often is thick and prominent in larger apothecia, a tall hymenium, spores of medium size, rather long conidia and the presence of substictic acid. Aspicilia substictica, also containing substictic acid, is separated from A. anglica by its thin, gray thallus, its small apothecia with thin and flat thalline exciple, and it grows at higher altitude (2900-3000 m) in Apache Co., Arizona. Aspicilia santamonicae, another brown species with elevated and often prominent thalline margin, contains norstictic acid and has shorter conidia. Aspicilia knudsenii differs by submoniliform paraphyses, usually shorter conidia and by having stictic acid as a major substance and norstictic acid usually in minor amounts. Two other specimens from Coconino County in Arizona, (altitude 1740-1900 m; Boykin 2775; Nash 31002; both in ASU), contains substictic acid. Microscopically they agree quite well with A. anglica, but they have a gray thallus and grow on calciferous rock. Further studies are needed to decide if they represent another taxon, or belong to A. anglica. A few specimens from San Gabriel Wilderness, Los Angeles County (Neel SG80; Ryan 26538, 26549 & 26561; all in ASU) differ from A. anglica by having a brown to gray-brown thallus with flat areoles, a flat to slightly raised thalline margin, and they contain norstictic acid and sometimes stictic or hyposalazinic acid in addition. The relationship with these specimens and A. anglica also needs further studies. Some sterile specimens from Los Angeles County, California (San Gabriel Wilderness: Neel SG142, Ryan 26608, 26550, 26558; Angeles National Forest: Ryan 26298; all in ASU) contain substictic acid. They often have a partly verrucose-areolate thallus, and are sometimes sorediate. They usually lack pycnidia, but one specimen (Ryan 26298) has pycnidia with short conidia (7-9 x 1 µm), in contrast to the filiform conidia in A. anglica. Further studies of the sterile specimens, preferably using DNA methods, are necessary.