A character for Acacia decora that I have just noticed in my reading is that the phyllodes are on raised stem projections, which can be seed in photo 2. This is easiest seen on branchlets where phyllodes have fallen off. See https://vicflora.rbg.vic.gov.au/flora/taxon/6f37dcce-adf8-48f8-99b9-18400991f5e7#&gid=1&pid=7