Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Life habit: lichenized Thallus: crustose to subsquamulose, warted or areolate cracked; prothallus: often well developed, black areoles: contiguous or often dispersed, convex upper surface: brown to red-brown or (often rather dark) gray, dull to slightly glossy medulla: white, I- photobiont: primary one a trebouxioid green alga, secondary one absent Ascomata: apothecial, immersed or sessile, black true exciple: persistent, with a small greenish or brownish black epihymenioid cortex and an usually unpigmented, opaque medullary part, (rarely) in section, K-, composed of +globose cells, usually without algae epihymenium: bright green, brown or partly violet in K hymenium: hyaline, I+ weakly blue (ascus walls); paraphyses: simple below, occasionally branched above, apical cells often swollen and +moniliform, lax and well separating in squash preparations; hypothecium: brown below, hyaline above (subhymenium) asci: +cylindrical or rarely clavate, Schaereria-type, thin-walled, not apically thickened, only outermost gelatinous layer I+ faint blue ascospores: hyaline, simple, +globose to ellipsoid or rarely bean-shaped, smooth, lacking a perispore Conidiomata: pycnidial, immersed conidia: bacilliform, simple, hyaline Secondary metabolites: a tridepside Geography: Northern and Southern Hemisphere, in cool to cold, mostly humid climates Substrate: acidic rocks. Notes: Schaereria is distinguished from other Lecidea s.l. groups by its thin-walled, cylindrical asci and lack of distinct apical thickening (tholus), and its thin and lax paraphyses.