Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Life Habit: lichenized, not lichenicolous or sometimes possibly on cyanophilic lichens Thallus: crustose, effigurate, squamulose, or placodioid, attached by the lower surface or by rhizines, appressed or with free lobe tips areoles/squamules: dispersed or adjacent or imbricate, up to 1.5 mm wide, rounded, crenulate, lobed or with incised margins, blastidia and soralia present or absent upper surface: white, gray, light green, or light to dark brown; dull or shiny, smooth, pruinose or not upper cortex: usually well developed and consisting of an upper epinecral layer and a lower stainable layer, the latter composed of irregularly or predominantly anticlinally oriented hyphae, containing remnants of algae (chlor-zinc-iodine!) and often crystals of secondary metabolites medulla: white, of intricately interwoven hyphae, not amyloid or weakly amyloid photobiont: primary one a chlorococcoid alga, secondary photobiont absent; algal cells: 10-15 µm in diam.; algal layer: horizontally continuous or interrupted by strands of cortical tissue lower cortex: present or absent lower surface: white to pale brown hypothallus: present or absent Ascomata: apothecial, lecanorine, circular, laminal to submarginal, subimmersed, sessile, or substipitate, with a more or less prominent, often disappearing thalline margin; up to 1 mm in diam.; disc: medium brown to brownish black, pruinose or not; exciple: pale to medium brown; hypothecium: hyaline to pale brown, lacking crystals; epithecium: pale to medium brown, K-, N-; hymenium: hyaline, amyloid, 40-70 µm high; paraphyses: weakly conglutinated, thin-walled, sparingly branched and anastomosing, often with a swollen apical cell, often with a sharply delimited, brown cell wall pigment in the upper part of the apical cell asci: clavate, with a well developed, evenly deeply amyloid tholus lacking an ocular chamber (Catillaria-type), 8-spored ascospores: 1-septate, ellipsoid to shortly bacilliform, often slightly constricted at the septum, hyaline, smooth, 6-20 x 3-6 µm Conidiomata: pycnidial, laminal, immersed conidia: pleurogenously formed, shortly bacilliform, 2-6 x c. 1 µm Secondary metabolites: orcinol and ß-orcinol depsidones, triterpenes and unidentified compounds Geography: temperate and subtropical regions of the world, center of diversity in Mediterranean Europe and North Africa Substrate: rock and soil, especially calcareous substrates. Notes: The Catillaria-type ascus and the pleurogenous, bacilliform conidia place Solenopsora in the Catillariaceae. The genera Catillaria A. Massal. and Placolecis Trevis. differ in having lecideine apothecia. In addition, Placolecis has simple ascospores. Halecania M. Mayrhofer differs in having halonate ascospores. Some Solenopsora species (e.g. S. candicans and S. olivacea) have effigurate, placoidioid thalli, but none of these are known from the Sonoran region.