Blechnum norfolkianum (Norfolk Island Water-fern)

Kingdom: Plantae
Division: Pteridophyta
Class: Polypodiopsida
Order: Polypodiales
(Unranked): Eupolypods
Family: Blechnaceae
Genus: Blechnum|
Species: B. norfolkianum
Binomial name: Blechnum norfolkianum
Synonyms: Lomaria norfolkiana, Blechnum lanceolatum var. norfolkianum, Lomaria acuminate, Spicanta acuminate, Blechnum acuminatum, Lomaria attenuate,
Common name: Norfolk Island Water-fern

Blechnum norfolkianum is an indigenous tufted fern common on Raoul Island (Kermadec Island group) and the Three Kings Islands, otherwise uncommon and sparingly distributed on mainly offshore islands from the Cavalli's south to Mayor Island. It is also the Chatham Islands from South East (Rangatira) Island. It is also on Norfolk Island where it is now seriously at risk of extinction.
Its habitat is strictly coastal. This species is most frequently seen on the outer Hauraki Gulf offshore islands. It favours shaded sites, usually in or near petrel colonies, or near penguin trails and nests.

Photographed at Otari-Wilton Bush, Wellington
Blechnum norfolkianum Norfolk Island Water-fern -001.JPG

Thin brown fertile fronds can be seen in the centre, Photographed at Otira Wilton Bush Reserve.
Blechnum norfolkianum Norfolk Island Water-fern-006.JPG 

The topside of a sterile frond.
Blechnum norfolkianum Norfolk Island Water-fern -002.JPG

The underside of a sterile frond.
Blechnum norfolkianum Norfolk Island Water-fern-004.JPG

Thanks to Wikipedia for text and information:

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