The taxonomic relationships between Phyllobacterium myrsinacearum LMG 2t2T, Phyllobacterium rubiacearum LMG 1t1T and two Phyllobacterium strains representing a collection of isolates from sugar-beet roots were investigated by means of fatty acid analysis and DNA-DNA hybridization. The strains showed very similar fatty acid compositions and more than 96% DNA reassociation to each other. On the basis of these results and available data from the literature, it is proposed that P. rubiacearum be classified as a junior subjective synonym of P. myrsinacearum, and that the sugar-beet isolates be included in the latter species. An emended description of P. myrsinacearum is given.