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, superficial, finely granular-sorediate to membranous or areolate, rarely almost squamulose surface: pale yellow or white photobiont: primary one a trebouxioid green alga, secondary one absent Ascomata: apothecial, biatorine, sessile, with an inconspicuous margin disc: red-orange to often deep red to red-brown, less often brown-black or black, usually soon convex, often slightly shiny exciple: composed of conglutinated, thick-walled, radially oriented hyphae, with an orange-red or less often brown outer part epihymenium: hyaline or red-brown, with orange-red to brown or (P. elabens) black granules, K+ red to reddish purple or black-red (in section) hymenium: colorless, strongly gelatinized, 50-60 µm tall, I+ blue; paraphyses: usually simple or sometimes branched towards apices, 1.5-2 µm wide, septate, constricted at the septa, with slightly clavate, weakly thickened tips; hypothecium: colorless asci: broadly clavate, Lecanora-type, with an amyloid tholus with ocular chamber, axial mass and broad apical cushion, with a non-amyloid outer ascus wall, 8-spored ascospores: hyaline, simple, broadly to narrowly ellipsoid, 7-14 x 5-8 µm or 8-12 x (2-)3-4(-5) µm, rather thick walled, brown when old, smooth, without a distinct perispore Conidiomata: pycnidial, immersed or often absent, not chambered conidia: long-bacilliform to filiform, mostly curved, over 10 µm long Secondary metabolites: thallus with xanthones or usnic acid, or ß-orcinol depsidones or ß-orcinol depsides; apothecia with anthraquinones Substrate: on bark or wood , or sometimes on rock Geography: Europe, Asia, North America, South America, and Australasia. Notes: Pyrrhospora species were treated as either Lecidea or Protoblastenia species for many years, but the genus was reintroduced by Choisy (1950) and later supported by Poelt and Vězda (1981). It is characterized by its Lecanora-type ascus and the presence of anthraquinones in the apothecia in most species. Pyrrhospora appears to be closely related to Lecidella. In the Pacific NW other common Pyrrhospora species on bark are the sorediate and usually sterile P. cinnabarina (Sommerf.) M. Choisy and the usually fertile P. gowardiana T. Sprib. & M. Hauck (Sbribille and Hauck 2003).