I am pretty certain that , that is Robinia pseudoacacia , Things can get complicated between local and botanical names ( nomenclature ) which is why it ( nomenclature ) exists ! Acacia dealbata ( mimosa ) is a very different wood indeed as are the classic acacias of the Africa plains . .... Nice bowl by the way !! The dark patches in the heartwood are not spalting , it is usually present as is a dark band between heart and sapwood , also the heartwood is very decay resistant and is sometimes known as golden oak , Robinia p is a member of the pea family and smells of it too when fresh just like Laburnum , it is also unpleasantly thorny on its twigs and does grow to a good size in the UK 3 foot + dia and 80 foot tall and is quite common in fact I will be taking one down quite soon so will have plenty of it , I also recently purchased some well seasoned natural edge boards for making some furniture .... Terry...