Does the tree have thorns? If so, you are welcome to email your photos to me at nathan@sepman.co.za and I will check with my South Africa tree books. If the tree does not have thorns, probably Mimosa, an Australian Wattle. Regards
Many acacias bear "phyllodes", flatted petioles that take the place of true leaves.
In your species, the phyllodes are found as immature "leaves" and the true leaves on the more mature stems are the finely pinnate (feathery) structures. You even show some intermediate forms.
There are many species of Acacia that bear phyllodes. The three most common are A. melanoxylon, A. decurrens and A. longifolia.
nathan_acacia
gardenguru1950
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