Rare Pittosporum Found

Fabulous Flora Found!

The predator control team at The Forest Bridge Trust recently made an exciting discovery. While setting up traplines within 165 hectares of QEII covenanted forest in Matakana, Cam, Steve and Alex, (independently of each other) spotted an unusual shrub. All of them noticed it was something they hadn’t seen before, and a photo was dispatched to Brenda Osborne, a local ecologist.

Brenda thought it could be the very rare Pittosporum kirkii, named for the renowned botanist Thomas Kirk who first recorded the plant on Great Barrier in 1867. Vice President of the Auckland Botanical Society, Maureen Young, went into the wilds with Brenda and Alex to look at the specimen and confirmed it was indeed P. kirkii. An extremely experienced botanist, Maureen has only encountered one other example of this plant in the Rodney area, back in 2010. NB, It’s well worth reading about that adventure in Maureen’s own words, in her article: “Pittosporum kirkii on Mt Tamahunga” (see link in references below).

P. kirkii grows at altitude and is found from Northland to the central North Island, including on Hauturu (Little Barrier) and Aotea (Great Barrier). But it is very sparse indeed, now classified as ‘At Risk’ (of extinction). As Maureen wrote in her article for the Auckland Botanical Society Journal reporting this latest find in Matakana, “By consulting the Australasian Virtual Herbarium distribution map I found that there were only two other, very old, records of P. kirkii growing in this general area”.

Normally an epiphytic plant (one which grows up high in trees), the recently discovered specimen was still growing epiphytically but close to ground level because its host northern rata tree had fallen down. By the time each member of the team noticed it, the P. kirkii was already redirecting its branches skyward in an effort to adapt to its new position!

As with so many other native plant species, P. kirkii’s current scarcity is down to forest clearance and introduced browsing animals. Possums are serious culprits, able to access the canopy to graze on P. kirkii’s juicy leaves and fresh shoots. But in the case of the one spotted by the predator control team, it potentially had far more to worry about – not only possums, but also ground dwelling pests like goats and pigs who would find everything about this rare plant delicious.

Trapping is a crucial part of protecting not only native bird life but also our unique plants, as this beautiful stretch of covenanted forest, and our observant predator control team, demonstrated so well with this amazing find.

References:

• Maureen Young, “Pittosporum kirkiii on Mt Tamahunga”: ak_bot_soc_journal_65_2_dec_2010_133-134.pdf (nzpcn.org.nz)
• Maureen Young, “More Pittosporum kirkii…growing in Rodney” Auckland Botanical Society Journal 78(1) June 2023 edition
• NZ Plant Conservation Network: Pittosporum kirkii • New Zealand Plant Conservation Network (nzpcn.org.nz)
• The Australasian Virtual Herbarium: The Australasian Virtual Herbarium

Photograph with thanks to Alex Wardenaar.