Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: pendent, filamentous, often very long, 6-45 (-90) cm, often draping tree branches, not brittle branching: anisotomic to submonopodial, usually frequent from the base branches: uneven in thickness, (0.2-) 0.4-1.5 (-4.0); main branches: foveolate and twisted, sometimes becoming dorsiventrally compressed and expanded toward the base; true lateral spinules: absent surface: yellow-brown to red-brown or dark red-brown, often variable within the same specimen, shiny or less frequently dull; pseudocyphellae: absent or sparse (perhaps only torsion cracks), depressed and elongate fusiform, white to pale brown soralia: rare, absent in most specimens, sparse when present (not seen in Sonoran material), tuberculate, pale to bright yellow, usually as wide as the branches on which they occur, up to 2.0 (-4.0) mm long Apothecia: absent or sparse, lateral; thalline exciple: concolorous with thallus, thin and soon becoming excluded, 1.0-2.0 (4.0) mm in diam.; disc: becoming convex at maturity, yellow pruinose asci: clavate, 8-spored ascospores: subglobose, simple, 5-8 x 4-5 µm Pycnidia: not seen Spot tests: cortex and medulla: K-, C-, KC-, P-, UV- (soralia and apothecia may be UV+) Secondary metabolites: no lichen substances, or vulpinic acid (in soralia and apothecia only). Substrate and ecology: on bark or wood, mainly conifers in dry, open forests, occasionally on hardwoods near the coast World distribution: Eurasia and western North America Sonoran distribution: southern California and northern Baja California. Notes: It is characterized by its usually shiny, broad, foveolate main stems and its characteristic yellowish brown to dark reddish brown color. It often forms long thick beards when dry. Although quite variable, well-developed material is difficult to confuse with any other species in California except possibly Nodobryoria oregana, which has a dull surface and jig-saw puzzle-like cortex in surface view and often has a few apothecia with brown discs. Records of B. fremontii from Arizona are dubious and are most likely poorly developed, non-sorediate specimens of B. fuscescens]. It may be extinct from the Sonoran region, as only one specimen collected in Riverside Co., California, by Hasse in 1904 was found.