Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: caespitose or sometimes decumbent, 2-4 (-5) cm long, forming small, rather dense tufts to slightly hanging, sometimes attached to the substrate at the tips as well as the base; base persistent branching: mainly isotomically dichotomous from the base; axils: usually acute, making the thalli appear brush-shaped branches: even in thickness, 0.2-0.4 mm in diam., straight or slightly curved, round or rarely slightly deformed (foveolate) surface: ± shiny, brown to dark brown to almost black, concolorous, or not much paler towards tips; lateral spinules: with slightly constricted bases, sparse to frequent, sometimes abundant; pseudocyphellae: absent soralia: abundant, fissural, sharply delimited, usually broader than the branches on which they occur, round or oval, white to brownish black or more usually greenish black; young soredial masses convex, the soralia becoming crateriform as the soredia are shed, lacking isidial spinules but sometimes bearing irregular, often contorted, non-isidiiform spinules Apothecia and Pycnidia: unknown Spot tests: cortex and medulla K-, C-, KC-, P-, UV-; soralia P- Secondary metabolites: none detected. Substrate and ecology: characteristically on well illuminated twigs and small branches, rare on soil or rock but often on lignum, almost always intermixed with B. lanestris and frequently also B. furcellata World distribution: circumpolar, mainly in continental areas Sonoran distribution: reported from Arizona (St. Clair and Newberry 1992) [not seen]. Notes: The species is characterized by greenish black, tuberculate soralia (rather than pale or at most speckled with brownish black, as in other North American species of Bryoria) and is always P-. According to Brodo and Hawksworth (1977) B. simplicior is quite frequently mixed with B. lanestris, which is similarly colored but has finer, pendulous branches and P+ red soralia.