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DescriptionLife habit: lichenized or facultatively lichenicolous; Thallus: crustose, warted or areolate cracked; prothallus: sometimes visible between areoles and forming a dark border to the thallus; surface: white, pale gray, green, or yellow (darkening to brown in older herbarium material), dull to glossy; medulla: white, I-; photobiont: primary one a chlorococcoid green alga, secondary one absent; Ascomata: apothecial, aspicilioid-lecanoroid or lecideoid, immersed or becoming sessile, immagrinate when young; disc: black, somewhat concave to strongly convex; margin: with a thalline one or not; exciple: thin, +inconspicuous; epihymenium: usually with purplish or greenish pigments (N+ red); hymenium: hyaline below, aeruginose or purple to green above; paraphyses: simple or sparingly branched, thick-walled, gelatinously coated and strongly swelling in water, hyaline to violet-brown, without swollen apices but often pigmented (green to black-violet); hypothecium: ochraceous below; asci: clavate, Lecanoratype, with an euamyloid tholus and a broad axial body, 8-spored; ascospores: hyaline, simple to rarely 1-septate, ellipsoid, without a distinct perispore, +thick-walled; Conidomata: pycnidial, immersed; wall: hyaline except for green pigmentation around the ostiole; conidia: hyaline, simple, cylindrical, oblong-ellipsoid to short and threadlike, +straight; Secondary metabolites: atranorin or usnic acid in the cortex; various depsidones and aliphatic acids in the medulla; Geography: arctic/alpine in Asia, Europe, and North America and rarely in Australasia; Substrate: non-calciferous rock, and lichen thalli.; Notes: Calvitimela differs from Tephromela in that the apothecia are convex and immarginate (e.g. lecideoid), its ascus structure (Lecanora-type instead of Bacidia-type), and the secondary chemistry of its thallus and hymenium. The apothecia are calvitiform ("like a bald spot") when young, a fact that explains the origin of the generic name. The third species, C. testaceoatra (Vain.) Hafellner, with psoromic acid may eventually be found in the region, as it is known from Colorado.