Life habit: lichenized Thallus: foliose, dorsiventral, lobed, often very large, spreading, orbicular and ± rosette-forming and radiate, or irregularly laciniate, or ± dichotomously or irregularly branched, or polyphyllous, rarely ± monophyllous, loosely to tightly adnate lobes: narrow and strap-shaped or broad, ± dichotomously branching with distinctly bifurcate apices which may be rounded, pointed or truncate, often imbricate; margins: entire or variously incised or folded, often free and ascending upper surface: blackish, brown, olive, green, blue-green, gray, ochraceous, yellow, or white, continuous, smooth or wrinkled, sometimes ± scabrid or hairy, sometimes shallowly foveolate, with faint or marked reticulum of interconnecting ridges, shiny or matt, often conspicuously maculate, with or without pseudocyphellae, isidia, phyllidia or soredia; cephalodia present or absent; goniocysts absent; margins often with conspicuous, elongate or verruciform pseudocyphellae upper cortex: paraplectenchymatous, anticlinally arranged, ± isodiametric, thick-walled cells medulla: loose, white or yellow photobiont: primary photobiont a cyanobacterium (Nostoc), or chlorococcoid alga (Dictyochloropsis or Chlorella-like); accessory photobiont (Nostoc) present in some green algal species lower cortex: paraplectenchymatous, anticlinally arranged, ± isodiametric, thick-walled cells lower surface: glabrous or usually ± tomentose, the tomentum pale to dark, thick and felted to indistinctly pubescent, always pseudocyphellate; pseudocyphellae: white or yellow, sparse to frequent, ± immersed in tomentum to raised-conical, round to irregular, the margins distinct or indistinct; attached to substrate by rhizoids which often form a mat Ascomata: apothecial, often absent but abundant in a few species, roundish, emergent, becoming sessile to substipitate, marginal or laminal, hemiangiocarpic; disc: brown or red-brown, dull or shining, sometimes white-pruinose, round, usually concave; thalline exciple: well developed, prominent or slightly prominent, entire or crenate-striate, phyllidiate, isidiate or sorediate in some species, smooth to verrucose or areolate-scabrid, hairy or maculate; true exciple: hyaline to yellow-brown; hymenium: hyaline and brown or olivaceous above; hypothecium: pale or dark, hyaline to ochraceous, brown or violet; paraphyses: unbranched, not anastomosing asci: clavate, Peltigera-type, unitunicate, with amyloid (I+ blue) cap in tholus, 8-spored ascospores: oblong-fusiform, fusiform, fusiform-ellipsoid, obtuse or apiculate at the poles, simple then polarbilocular to transversely 1-3 (-5)-septate, wall hyaline becoming pale to dark brownish, grayish, or blackish, smooth, 20-38 (-43) x 6-11 µm Conidiomata: pycnidial, laminal-lateral, immersed, Lobaria-type, globose or ovoid, 0.2-0.6 mm diam., walls dark brown at ostiole, paler below conidia: straight, cylindrical, bacilliform, or bifusiform, 3-5 x 0.7-1 µm Secondary metabolites: orcinol depsides, ß-orcinol depsides (including atranorin) or depsidones, terphenylquinones, pulvinic acid derivatives, usnic acids; triterpenoids (hopanes, stictanes, lupanes, and fernenes) Geography: temperate (primarily Southern Hemisphere) to tropical Substrate: on bark, wood, soil, detritus, or non-calciferous, siliceous rock, in humid, sheltered, oceanic woodlands. Notes: It is characterized by the presence of pseudocyphellae on lower (and sometimes upper) surface, emergent apothecia with colorless or brown, 1-3 septate or polarbilocular spores, and a diverse chemistry.