The New Zealand Plant Conservation Network

Can anybody shed any light on which species the Pittosporum sold as Pittosporum 'Stephens Island' conforms most closely to ? According to Eagle's, P. ralphii does not grow down that far, and it doesn't look like P. colensoi.

Stephens Island Pittosporum is a morphological intermediately between Pittosporum tenuifolium and Pittosporum crassifolium (Prof. B. D. Clarkson, pers. comm., University of Waikato 2011)

Hi Philip,

Last I heard about this one - and that was a long time ago (I stress that) was that Dr Chrissen Gemmill (Universty of Waikato) thought it was a new species and was going to formally name it. For me I'd first like to see a thorough critical revision of the Pittosporum tenuifolium complex, using multiple DNA markers and AFLP data coupled with modern morphometrics before I'd get that excited about the Stephens Island "race" being anything else but a race. Either way its a nice plant, popular in cultivation right now, and, funny thing, horticulturists often figure out new species by growing them long before taxonomists get around to recognizing them...so you never know.

Cheerio

Peter J. de Lange

In 2009 I submitted my masters thesis on hybridisation in NZ Pittosporum. I found that P "Stephens Island" had an identical trnT-trnL (chloroplast DNA) sequence to P. colensoi and P. tenuifolium, so I would say it most closely related to these species but in general the sequence variation is very low between species. I don't know if more work has been done recently on this.

cheers,
Susan Carrodus

Sorry just to add to that, this doesn't mean it is not a hybrid between P. tenuifolium and another species such as P. crassifolium.

Thanks for all of that information. It's interesting to know all of that because, as I said, it's characters are quite ambiguous - from the visual standpoint of a horticulturist. And I've not really seen any unequivocal statements on its identity.