  Nilpotent Lie groups with stepwise square integrable representations were
recently investigated by J.A.~Wolf. We give an alternative approach to these
representations by relating them to the stratifications of the duals of
nilpotent Lie algebras, thus proving that they correspond to a subset with
relative Hausdorff topology, dense interior, and total Plancherel measure in
the unitary dual of the Lie group under consideration.
