Unfortunately the diagnostics for wattles with true leaves include where the glands are on the rachis (stalk) at the bases of the leaflets, and the shape of the branchlets. Your photo of the back of a leaf rules out dealbata, which is hairy on the backs of the leaflets. The widelt spaced very narrow leaflets sugest decurrens. http://worldwidewattle.com/imagegallery/image.php?p=0&l=d&id=16975&o=1