Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Thallus: crustose, effuse, 10-20 mm in diam., thin (70-200µm thick), rimose-membranaceous; prothallus: not evident areoles: sometimes pulvinate surface: beige to green-gray or gray-brown (white to pale or gray-brown when wet), smooth, with a slightly oily gloss, esorediate cortex: phenocortex, 8-15 µm thick, the end cells of the hyphae capitate-thickened with dark brown pigment caps photobiont: Myrmecia-type, the cells 8-12 µm long, ellipsoid, ovoid or ±oblong, always with distinct haustoria (sometimes 2 per cell); algal layer: 30-70 µm thick, the algae scattered medulla: very thin, mostly endolithic or in the center of pulvinate areoles forming a loose network Apothecia: solitary, scattered or densely crowded into small groups and then mutually deformed, sessile, slightly constricted at base, 0.1-0.2(-0.3) mm in diam., urceolate to cup-shaped (young apothecia with almost punctiform disc) disc: black (when wet pale to dark brown, the margin dark brown to black), slightly oily, shiny; margin: distinct, swollen exciple: lenticularis-type, brown or dark brown in outer zone (ends of hyphae with dark brown pigment caps), not carbonaceous, ±hyaline within, in lower part containing scattered algae epihymenium: dark brown, K-, N+ violet, 9-17 µm thick hymenium: hyaline, I+ blue then brownish violet (gelatinous coat of asci ±red, hymenial gelatin violet, ascus tip blue, or sometimes entire hymenium blue), (40-)50-70 µm tall; paraphyses: lenticularis-type, easily free, simple to furcate, the tips clavate-capitate-thickened, with pigment cap (pigment deposited in the hyphal wall); hypothecium: hyaline, 30-80 µm thick, with scattered algae asci: subcylindrical, (40-)45-58 x 10-16 µm, the wall 2-2.5 µm; tholus I+ blue, 8-spored ascospores: hyaline, 1-septate, often still in ascus, ellipsoid, mostly 10-16 x 4.5-6 µm Pycnidia: unknown Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on nutrient-enriched (e.g., by birds) siliceous rocks (quartz, quartzite) World distribution: Europe (England) and North America Sonoran distribution: southern California. Notes: Catillaria subviridis belongs to the C. chalybeia group. The asci are "Lecanora-type" according to the description in Kilias, but his fig. 25 shows a mostly amyloid apex, as in Catillaria-type sensu Hafellner but with an axial canal extending only partly upward from the tip of the endoascus, ±as in Bacidia-type sensu Hafellner but without an ocular chamber. In Europe it primarily occurs in cool, highly oceanic habitats, and consequently the report of this species from warm areas of southern California are potentially incorrect, particularly as Coppins (1992) has suggested that it may be endemic to the Isle of Scilly. Unfortunately material identified under this name was not available for checking.