Just about a year ago I posted a photo of Pittosporum cornifolium in fruit. Perhaps I should have looked more closely, because right now it's in flower as well, so it probably was then too. The flowers are dark red, like P. crassifolium and others, at least on the outside of the petals, but unlike them P. cornifolium has narrowly acute petals.
Pittosporum cornifolium, cultivated plant at Victoria University
P. kirkii has petals like that, but they're yellow, the sepals are reflexed, and the tip of the branch has large papery bracts:
Pittosporum kirkii, cultivated plant at Victoria University
The diversity of flowers and sexual systems in New Zealand Pittosporum is amazing; it suggests a diversity of pollinators and a comparative study would make a great thesis for someone. There's a detailed account of P. cornifoliumhere.