Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Life habit: lichenicolous Thallus: endokapylic or epikapylic, sometimes causing damages to the host photobiont vegetative hyphae: colorless, not amyloid Ascomata: apothecial, sessile, narrowly attached, constricted at the base, round, scattered to +aggregated disc: plane to convex, cream or pale brown to dark brown or black, dull to shiny margin: distinct to very distinct, pale brown to dark brown or black exciple: prominent, composed of parallel, regularly radiating, branched, anastomosing, strongly agglutinated hyphae, outermost parts colorless, pale brown to dark reddish brown, apically with an unevenly distributed granular, greenish brown to greenish black pigment, internally colorless greenish brown to red brown epihymenium: not continuous, with an unevenly distributed granular, greenish brown to greenish black pigment which occasionally follows the paraphyses downwards hymenium: colorless, sometimes pale brownish to greenish black in upper parts; hymenial gel: hemi-amyloid, ILugol paraphyses: septate, very sparingly branched and with a few anastomoses, apical cells slightly thickened to clavate; subhymenium: colorless hypothecium: composed by loosely intricated hyphae, colorless to brown asci: cylindrical to subclavate, Scutula-type with amyloid tholus and diffuse non-amyloid axial body, outer amyloid wall layer c. 0.2 µm thick, ILugol 1:6 + blue to bluish brown, ILugol + reddish brown to red or blue, ILugol conc + reddish brown to red, non-amyloid wall layer c. 0.6-0.8 µm thick, ascus basis bifurcate, cell below ascus with crozier, 6-8 spored ascospores: hyaline, (0-)1(-3)-septate, narrowly ellipsoid to broadly ellipsoid, ends usually attenuated, sometimes with oil droplets, thin- walled, smooth pycnidia: globose, subimmersed to sessile; wall: apically colorless, red to dark brown, blackish brown or greenish black, basally colorless to pale brownish, +pseudoparenchymatic microconidia: hyaline, simple, bacilliform to filiform, sometimes curved soconidia: hyaline, simple, bacilliform to falcate, often irregular in shape conidia: hyaline, 0-1-septate, oblong cylindrical to bacilliform, often somewhat irregular in shape, base truncated Geography: Europe, Africa, Australasia, South America, and North America Substrate: lichens, mainly Peltigeraceae.
Kistenich, S., E. Timdal, M. Bendiksby & S. Ekman. 2018. Molecular systematics and character evolution in the lichen family Ramalinaceae (Ascomycota: Lecanorales). Taxon 67(5): 871–904.
Notes: Scutula is expanded to include lichen-forming species without parasitic life stages: S. circumspecta (Vain.) Kistenich & al. and S. effusa (Rabenh.) Kistenich & al., both formerly in Bacidia, based on molecular evidence.