Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Thallus: pendulous, up to 250 cm long, stiff, poorly to moderately branched branching: anisotomous-dichotomic, parallel basal part: concolor with or paler than branches, with distinct annulations, often with many points of attachment branches: cylindrical to irregular; lateral branches: not narrowed at point of attachment segments: cylindrical to slightly trapezoidal, weakly to strongly ridged, sometimes slightly alate, rarely with erose cortex papillae: conspicuous, abundant, large, cylindrical to truncate-conical, paler at top, sometimes eroded, irregularly distributed mainly on secondary and thinner branches tubercles and fibercles: absent fibrils: short (0.5-2 mm) to long (3-10 mm), mostly spinulose, in a fish-bone like arrangement soralia and isidiomorphs: absent pseudocyphellae: short and linear, inconspicuous on secondary and thin branches cortex: thin to moderately thick (5-12%) medulla: thin and compact, non pigmented axis: thick, often fistulose at base of main branches Apothecia: up to 2 cm in diameter, lateral Spot tests: K+ yellow turning red, C-, KC-, P + orangish yellow, or K-, C-, KC-, P- Secondary metabolites: salazinic acid or caperatic acid. Substrate and ecology: on bark World distribution: Africa and southern North America Sonoran distribution: Baja California Sur and Chihuahua. Notes: Usnea goniodes is closely related to U. transitoria, differing only by the production of numerous apothecia and the absence of soralia.