Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Life habit: lichenized Thallus: subfoliose to foliose, orbicular, growing loosely attached, frequently with a fibrous, well-developed hypothallus that sometimes extends as a blue-black zone around the thallus lobes: flat to concave, sometimes producing isidia or soredia marginally upper surface: mostly bluish gray, often smooth, scabrid or pruinose upper cortex: paraplectenchymatous photobiont: primary one a Nostoc, secondary photobiont absent lower surface: naked and whitish, with bluish black rhizohyphae Ascomata: apothecial, sessile, mainly laminal, usually with a crenulate thalline margin obscuring the proper one; disc: flat, often becoming convex, orange- or reddish brown to black; hymenium: I+ blue in vicinity of asci asci: apically thickened , but without internal amyloid structures, 8-spored; ascospores: simple, colorless, ellipsoid, often apiculate at one or both end and with conspicuous epispore or epispore Conidiomata: pycnidial conidia: straight, bacilliform Secondary metabolites: pannarin and related substances Geography: widespread in warm temperate to subtropical, forested habitats Substrate: on rocks and bark, particularly ones with bryophytes. Notes: In contrast to the squamulose Parmeliella and Fuscopannaria genera, Pannaria now includes most of the foliose or subfoliose species. The thalline margin of the apothecial discs in Pannaria contrasts with the athalline, proper margin of Parmeliella. Most species of Pannaria contain pannarin and hence are P+ red.