Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: shrubby, erect, decumbent or subpendent to pendent branching: aniso- or isotomic-dichotomous branches: ± terete and smooth, often hair-like, occasionally becoming flattened or angular and ± pitted (foveolate) especially on the main branches and towards the base, never markedly expanded and dorsiventrally compressed surface: continuous, usually dark reddish brown, sometimes pale grayish to yellowish brown, greenish to black, or partly greenish yellow (vulpinic acid); soralia: absent to abundant, tuberculate or fissural; pseudocyphellae: absent to abundant, usually sparse and inconspicuous, sometimes elongate and spiralling around in the main stems, usually fusiform, depressed to somewhat raised; soralia and pseudocyphellae: white to greenish or blackish, or rarely bright greenish yellow; isidia: absent but isidia-like spinules arising in tufts from soralia in a few species; true lateral spinules: present or absent cortex: composed of periclinal, conglutinate hyphae immersed in moderate or relatively little matrix medulla: hyphae usually not ornamented; cell walls with Cetraria-type lichenan and often also with isolichenan photobiont: primary one a trebouxioid alga, secondary photobiont absent Ascomata: apothecial, infrequent and unknown in some species, lateral, sometimes appearing geniculate, roundish, sessile; thalline exciple: slightly prominent to prominent, persistent to excluded, concolorous with thallus; disc: brown to dark brown, rarely white, sometimes yellowish pruinose; exciple: hyaline asci: clavate, 25-45 x 9-15 µm, Lecanora-type, the wall 1-1.5 µm thick, (6-) 8-spored ascospores: broadly ellipsoid to subglobose, simple, hyaline, smooth, without perispore or a distinct endospore thickening, I-, 4-12 (-14) x (2.5-) 4-7.5 µm Conidiomata: pycnidial, immersed, usually rare conidia: cylindrical to fusiform, minute Secondary metabolites: cortex with unknown brown pigments (usnic acid lacking), medulla with orcinol depsides, orcinol depsidones, ß-orcinol depsides, ß-orcinol depsidones, or pulvinic acid derivatives Geography: in the Northern Hemisphere circumarctic and circumboreal, temperate-montane to alpine and with a few species in mountainous areas in the Southern Hemisphere. Substrate: on bark, wood, rock or soil. Notes: The genus is usually easily recognized by its shrubby to vine-like or hair-like, mostly brown to black or grayish thallus, ± terete branches with a loose interior surrounded by arachnoid medullary hyphae. This genus is still very difficult because of challenges doing spot tests (McCune and Rosentreter 1993 and McCune and Goward 1995). In addition, non-sorediate specimens of typically sorediate species occur, and the close intermixing of different species is frequent. Thallus colors are best compared in sunlight, or against a dark or neutral (not pale) background. In separating apparent mixtures, care must also be taken to follow the branches to their basal parts rather than breaking off apical or basal parts that may look quite different from the main parts of the thalli, to which they are connected. Several additional species of Bryoria, as well as the similar genus Sulcaria (S. isidiifera Brodo) have been reported from just north of the Sonoran region in California (Riefner et al. 1995).