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 20(30) cm long branching: sparingly and dichotomously branched, growing from a narrow holdfast branches: solid, weakly or strongly canaliculate, adjoining branches often anastomosed, 1-3 mm wide surface: yellowish green, smooth, shiny, often with isidia-like swellings along the edge of branches, without soredia pseudocyphellae: common, mostly marginal or rarely laminal, linear cortex: thin; chondroid strands: continuous, heavily cracked Apothecia: common, stipitate disc: flat to +concave, without white margin; margin: concolorous with the thallus asci: elongate-clavate, 8-spored ascospores: hyaline, 1-septate, narrowly fusiform, 22-32 x 3.5-4 µm Pycnidia: not observed Spot tests: cortex K-, C-, KC+ yellow, P- medulla: K-, C-, KC-, P- Secondary metabolites: cortex with usnic acid (major); medulla with sekikaic acid (major) and 4'-O-demethylsekikaic acid (minor). Substrate and ecology: on bark World distribution:: southern North America and Central America Sonoran distribution: Sinaloa, more common in southern states of Mexico at elevations between 800 to 1200 m. Notes: Ramalina alludens is characterized by canaliculate branches without soredia, marginal continuous pseudocyphellae, heavily cracked chondroid strands in the branches, narrowly fusiform ascospores and by the presence of depsides such as divaricatic acid or sekikaic acid as major chemical metabolites in the medulla. Two chemical races of R. alludens, Race 1 (sekikaic acid containing race) and Race 2 (divaricatic acid containing race) are found in the Sonoran area. Differences between R. canalicularis and R. subcalicalis are given under those species.