I spent yesterday afternoon in the fernery of Otari-Wilton’s Bush, examining two tree fern species from New Zealand’s subtropical Kermadec Islands. More details below, including ‘why?’. But first, a challenge…
Each of these Kermadec tree ferns is closely related to a (different) mainland New Zealand species. Can you tell which mainland species?
One of the mainland species is well known by New Zealanders, at least in name, which is a big clue in itself. That one might be easy; the other is much harder.
Leave a comment below if you think you can identify their mainland relatives.
For help, try Te Papa’s online guide to New Zealand tree ferns.
The Kermadec Islands
The tree ferns Cyathea kermadecensis and Cyathea milnei are indigenous only to Raoul Island, the largest of the Kermadec Islands. Raoul Island is about 1000 km north-east of the North Island, and has a subtropical climate.
This public garden in Wellington is devoted to New Zealand’s indigenous plants. It is a wonderful place to see some of New Zealand’s most interesting plants. It is also a great scientific resource, bringing together plants from all over New Zealand.
Te Papa’s collection of dried, plants contains multiple specimens of Cyathea kermadecensis and Cyathea milnei. But whole fronds of tree ferns are rarely collected; they’re just too big! And very few entire tree fern fronds have come all the way from the Kermadec Islands.
This left Pat Brownsey and me short of measurements for our work on tree ferns for the electronic Flora of New Zealand. Fortunately the plants cultivated at Otari-Wilton’s Bush allowed us to address those gaps. Visiting these gardens is far easier than getting to the Kermadec Islands themselves.