This plant I saw earlier in the year (see 8th April on this blog) and with more or less regular outline to the leaves it resembled M regia. Recently I returned to this splendid garden in Perth and the rosette had expanded to a large flowering spike. The large flowers were a clear cream yellow with a dark stigma. It still looks typical of the species M. regia but it is in fact what we now call  M. 'napaulensis' hybrids - which originally would have included genes from M. regia and is rather a nice throwback to the true species.