Gully fern, also called pākauroharoha and Pneumatopteris pennigera, is one of the most common ferns in New Zealand. You’ll have almost certainly seen it if you’ve ever walked in a New Zealand forest. It occurs from the north of the North Island to the south of the South Island (although it is absent from much of the eastern South Island).
Gully fern belongs to the Thelypteridaceae family of ferns. The electronic Flora of New Zealand (eFloraNZ) chapter for the Thelypteridaceae has now been published. The eFloraNZ summarises what is known about the appearance, relationships, and distribution of New Zealand’s plants.
As with all eFloraNZ chapters, the Thelypteridaceae chapter come in two forms:
- the web version. With its hyperlinks, this is good for browsing through. And it has bigger pictures.
- the pdf version. (6 MB.) This is good if you prefer a more book-like experience. You can print the pdf, and go offline.
Diversity and distributions
The Thelypteridaceae is one of the world’s biggest fern families, with some 1000 species. When I’m working in the Pacific Islands, I find the diversity of the Thelypteridaceae challenging. There are lots of species, and many of the differences among them are subtle.
But in New Zealand the situation is much simpler as there are just five species. It would seem New Zealand is generally a bit cold for the Thelypteridaceae!
Of the five indigenous species, only gully fern is common and widespread in New Zealand; it also occurs in Australia. The other four occur even more widely outside New Zealand, into the Pacific Islands and tropical areas beyond.
One species, Macrothelypteris torresiana, is present in the New Zealand region only on the Kermadec Islands far to the north of the North Island (although it was seen once on the North Island’s North Cape).
The remaining three species – Christella dentata, Cyclosorus interruptus, and Thelypteris confluens – are scattered through the northern North Island. All three of them reach their southern distribution limits in the central North Island where geothermal areas somewhat replicate their usual tropical environments.
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