Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: fruticose, pendulous or decumbent, up to 10 cm long branching: sparingly and dichotomously branched, growing from a common holdfast branches: solid, terete, often ending with nodules, 1-3 mm wide surface: yellowish green, smooth, shiny, esorediate pseudocyphellae: common, marginal or rarely laminal, linear cortex: thin; chondroid strands: continuous, smooth Apothecia: common, stipitate disc: flat to +concave, slightly pruinose, without white margin; margin: entire, concolorous with the thallus asci: elongate-clavate, 8-spored ascospores: hyaline, 1-septate, broadly fusiform, 15-21 x 4.5-7 µm Pycnidia: not observed Spot tests: cortex K-, C-, KC+ yellow, P-; medulla K-, C-, KC-, P- Secondary metabolites: cortex with usnic acid; medulla with (Race 1) sekikaic acid (major) and 4'-O-demethylsekikaic acid (minor); (Race 2) divaricatic acid (major) and 4'-O-demethyldivaricatic acid (minor). Substrate and ecology: on volcanic rocks World and Sonoran distribution: moderately common in Baja California Sur and extending into Sinaloa. Notes: Ramalina canaliculata Tayl., R. fastigiata ssp. subcalicaris and R. subfraxinea var. subcanaliculata Nyl., all described from Mexico, are other Ramalinae with linear pseudocyphellae along main branches and broadly fusiform spores. The holotype specimens of the latter three are identical with the type of R. alludens morphologically and chemically. Ramalina alludens might be confused with R. canalicularis that differs in having tuberculate pseudocyphellae and in producing salazinic acid. Ramalina wigginsii resembles a morphotype of R. usnea with marginal continuous pseudocyphellae, from which it can be distinguished by its broadly fusiform spores.