On the surface of healthy land plants (embryophytes), numerous non-pathogenic bacteria have been discovered and described. Among these epiphytic microbes, pink-pigmented facultative methylotrophic microbes of the genus Methylobacterium are of special significance, because these microorganisms consume methanol emitted via the stomatal pores and secrete growth-promoting phytohormones. Methylobacterium funariae, Schauer and Kutschera 2011, a species isolated in our lab from the common cord moss, described as a nova species in this journal, was recently characterized for a second time as a "new taxon" under a different name, "M. bullatum." Based on a phylogenetic analysis, we show that these taxa are identical. In addition, we provide novel information on the exact cell size, and describe the correct type locality of this bacterial species, which was classified as a phytosymbiont. Finally, we discuss the hypothesis that certain methylobacteria may preferentially colonize bryophytes. With reference to our recent discovery that thalli of ferns form, like liverworts and moss protonemata, associations with methylobacteria, we argue that the haploid phase of cryptogames are preferred host organisms of these pink-pigmented microbial phytosymbionts.
Keywords: growth-promoting bacteria; methylobacteria; mosses; phytosymbionts; plant-microbe-interactions.