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Tephromela spp.
Family: Tephromelataceae
Tephromela image
Stephen Sharnoff  
Life habit: lichenized or lichenicolous Thallus: lacking (actually endokapylic) in lichenicolous species, otherwise crustose, warted or areolate cracked; prothallus: sometimes visible between areoles and forming a dark border to the thallus surface: white, pale gray or yellow-green (some darkening to brown in older herbarium material), dull to glossy medulla: white, sometimes cretaceous, I- photobiont: primary one a chlorococcoid green alga, secondary one absent Ascomata: apothecial, lecanorine or aspicilioid-lecanoroid , usually sessile, sometimes stipitate disc: black, somewhat concave to strongly convex; thalline exciple: present or absent true exciple: thin, +inconspicuous; epihymenium: usually with purplish or greenish pigments (N+ red) hymenium: hyaline below, purple to green above; paraphyses: simple or sparingly branched, thick-walled, gelatinously coated and strongly swelling in water, hyaline to violet-brown, apices not swollen but often pigmented (green to black-violet); hypothecium: ochraceous below asci: clavate, Bacidia-type s.l., 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 to filiform, +straight Secondary metabolites: atranorin or lichexanthone in the cortex; various depsidones and fatty acids in the medulla Geography: arctic/alpine, and temperate in Australasia, Asia, Europe, and North America with centers of speciation in tropical regions Substrate: non-calciferous rock, rarely limestone (T. cypria), bark, wood, mosses, and lichen thalli. Notes: Tephromela was resurrected by Hafellner (1984) to accommodate a few species previously assigned to Lecanora. Later, the concept of the genus was revised to include lecideoid species and, based on shared hymenial characters, subsequently it was enlarged by including lichenicolous species (formerly Nesolechia, Phacopsis) as well. Its unique features include a poorly developed true exciple, Bacidia-type asci, paraphysis structure and the occurrence of conidiogenous cells in chains. Recently the lecideoid species were transferred to Calvitimela (Hafellner and Türk 2001), as they proved to have a different ascus type.
Species within Saguaro National Park