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DescriptionThallus: foliose to subfruticose, closely adnate to semi-erect, cushion-forming, up to c. 6 cm diam., lobate; lobes: rather elongate, ± swollen, stiff, 0.5-1.5 mm wide, contiguous to separate or loosely overlapping; attached by basal holdfasts; upper surface: pale gray to nearly black, generally somewhat shiny (at least towards lobe tips), convex; soredia, isidia, and thallus perforations lacking, but regeneration lobules occasionally present; upper cortex: paraplectenchymatous and covered in a thin polysaccharide-like layer (nonpored epicortex); medulla: white throughout; cell walls containing Cetraria-type lichenan; photobiont: primary one a trebouxioid alga, secondary photobiont absent; lower cortex: palisade plectenchymatous, lacking polysaccharide-like covering; lower surface: tan or black, dull, becoming wrinkled, without rhizines; Ascomata: apothecial, laminal, circular, sessile with a prominent thalline margin; disc: concave, nonperforate, up to 5 mm diam.; exciple: gray or hyaline; epihymenium: brown or ochraceous-yellowish; hymenium: hyaline, usually with unbranched paraphyses; hypothecium: hyaline; asci: clavate, Lecanora-type, 8-spored; ascospores: ellipsoid, obtuse at the poles, colorless, simple, 8-12 x 6-8 µm, wall smooth, without distinct endospore thickening, I-; Conidiomata: pycnidial, black, laminal-lateral, immersed in upper cortex; conidia: normally bifusiform (6 x 1 µm); Secondary products: ß-orcinol depside, orcinol and ß-orcinol depsidones; Geography: arctic and alpine in the Northern Hemisphere; Substrate: on siliceous rocks, not calciferous.; Notes: Brodoa differs from Hypogymnia in that the lower cortex is palisade plectenchymous without a polysaccharide-like layer, the medulla is always solid, the thallus lacks perforations, the spores are larger, and it grows only on rocks in arctic-alpine areas. Apparently it is related to Allantoparmelia, which differs in having a brown upper surface (lacking atranorin) and isolichenan in the cell walls. Superficially it might be confused also with loosely adnate species of Lobothallia, but that crustose to subfoliose genus occurs at low to moderate elevations, is usually K+ yellow then red, and has a very different ascocarp anatomy with larger spores.