A novel Gram-positive-staining actinomycete designated strain GMKU095(T) was isolated from surface-sterilized roots of Acacia auriculiformis A. Cunn. ex Benth. (earpod wattle). The organism produced branching mycelium. The spores were non-motile and had a spiny surface. Growth of strain GMKU095(T) occurred at 18-42 degrees C, pH 5.0-8.0 and at NaCl concentrations up to 5 %. Whole-cell hydrolysates contained arabinose and galactose as major characteristic sugars. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The glycan moiety of the murein contained acetyl residues. The menaquinone was MK-8(H(4)); mycolic acids were not detected. The G+C content of the DNA was 71.6 mol%. iso-C(16 : 0) was detected as the major cellular fatty acid. Comparative studies of 16S rRNA gene sequences indicated that the strain was phylogenetically related to members of the genus Pseudonocardia. The most closely related type strain is Pseudonocardia spinosispora IMSNU 50581(T), which is 96.2 % similar in 16S rRNA gene sequence. On the basis of the genotypic and phenotypic properties presented, a novel species of the genus Pseudonocardia is proposed, Pseudonocardia acaciae sp. nov. The type strain is strain GMKU095(T) (=NRRL B-24609(T) =BCC 28481(T) =TISTR 1862(T) =NBRC 104274(T)).