Two endophytic strains, coded MOVP5T and MOPV6, were isolated from nodules of Phaseolus vulgaris plants grown on agricultural soil in Southeastern Spain, and were characterized through a polyphasic taxonomy approach. Their 16S rRNA gene sequences showed 99.3 and 99.4 %, 98.9 and 99.6 %, and 99.0 and 98.7% similarity to ‘
A. deltaense
’ YIC 4121T,
A. radiobacter
LGM 140T, and
A. pusense
NRCPB10T, respectively. Multilocus sequence analysis based on sequences of recA and atpD genes suggested that these two strains could represent a new
Agrobacterium
species with less than 96.5 % similarity to their closest relatives. PCR amplification of the telA gene, involved in synthesis of protelomerase, confirmed the affiliation of strains MOPV5T and MOPV6 to the genus
Agrobacterium
. Whole genome average nucleotide identity and digital DNA–DNA hybridization average values were less than 95.1 and 66.7 %, respectively, with respect to its closest related species. Major fatty acids in strain MOPV5T were C18 : 1 ω7c/C18 : 1 ω6c in summed feature 8, C19 : 0 cyclo ω8c, C16 : 0 and C16 : 0 3-OH. Colonies were small to medium, pearl-white coloured on YMA at 28 °C and growth was observed at 10–42 °C, pH 5.0–10.0 and with 0.0–0.5 % (w/v) NaCl. The DNA G+C content was 59.9 mol%. These two strains differ from all other genomovars of
Agrobacterium
found so far, including those that have not yet given a Latin name. The combined genotypic, phenotypic and chemotaxonomic data support the classification of strain MOPV5T as representing a novel species of
Agrobacterium
, for which the name Agrobacterium leguminum sp. nov. is proposed. The type strain is MOPV5T (=CECT 30096T=LMG 31779T).