Rough sword fern
Nephrolepis hirsutula (G.Forst.) C.Presl auct. non. New Zealand authors, Nephrolepis exaltata (L.) Schott auct. non. New Zealand authors
Vascular – Native
2n = 82
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | At Risk – Naturally Uncommon | Qualifiers: RR, SO
Previous conservation statuses
2009 | At Risk – Naturally Uncommon | Qualifiers: SO, OL
2004 | Range Restricted
Indigenous. Kermadec Islands (Dayrell, Raoul, Macauley and Curtis islands). Common throughout the Pacific and Australia, and extending into Malesia and India. Probably more widespread than this but the exact application of the name outside our region is unclear
Common throughout the dry and wet forest habitats of Raoul Island and in open shrubland, around thermal vents and the craters of Raoul. Sometimes found as a low epiphyte. On Macauley Island it is much less common but has been collected growing under Kermadec ngaio (Myoporum kermadecense Sykes).
Stout, rhizomatous fern forming dense patches. Rhizomes short-creeping to erect, producing numerous stolons. Stipes and rachises pale brown, brittle. Frond lamina ellliptic to narrowly elliptic, pinnate 300-2000 x 100-250 mm, dark green or yellow-green. Pinnae 40 or more pairs, the longest 50-150 x 8-16 mm, bearing pale brown scales with fringed margins on lower surface, slightly falcate often with a basal acroscopic lobe, tapering to an acute apex, margins irregularly toothed.
Not closely related to either N. flexuosa Colenso or N. cordifolia (L.)C.Presl. On Raoul it is sympatric with N. flexuosa from which it differs by the much longer, sickle-shaped pinnae whose undersides are covered by fringed scales. From N. cordifolia it further differs by its lack of tubers.
Not applicable - spore producing
Not applicable - spore producing
Easily grown from rooted pieces and fresh spores. Cold sensitive. In ideal conditions a very fast growing fern that can become invasive. An excellent pot plant. Best grown in partial shade, in a rich, moist but free draining soil.
Not Threatened. Listed only because in New Zealand it is confined to the Kermadec Island group where it is abundant on Raoul Island and very local on Macauley Island. It is not regarded as threatened overseas.
nephrolepis: Kidney scale
Where To Buy
Not commercially available
Plants from the Kermadecs have been variously referred to as Nephrolepis exaltata (L.) Schott and N. hirsutula (G.Forst) C.Presl. Recently Hovenkamp & Miyamoto (2005) placed Kermadec material within N. brownii. This action was initially followed by de Lange et al. (2006) but on advice from P.J. Brownsey and W.R. Sykes the Kermadecs Nephrolepis was then referred back to N. hirsutula in de Lange & Rolfe (2010). Recently, it has been decided that the Kermadec islands Nephrolepis is indeed N. brownii (de Lange 2015; L.R. Perrie pers. comm.). So that name is reinstated here.
Fact sheet prepared for NZPCN by P.J. de Lange 10 August 2005. Description from Brownsey & Smith-Dodsworth (2000).
References and further reading
Brownsey, P.J.; Smith-Dodsworth, J.C. 2000: New Zealand Ferns and Allied Plants. Auckland, David Bateman.
de Lange, P.J. 2015: Vegetation succession and flora of Macauley Island, Southern Kermadec Islands group. Bulletin of the Auckland Museum 20: 207–229.
de Lange, P.J.; Sawyer, J.W.D.; Rolfe, J.R. 2006: New Zealand Indigenous Vascular Plant Checklist. Wellington, New Zealand Plant Conservation Network. 94pp.
de Lange, P.J.; Rolfe, J.R. 2010: New Zealand Indigenous Vascular Plant Checklist. Wellington, New Zealand Plant Conservation Network. 164pp.
Hovenkamp, P.H.; Miyamoto, F. 2005: A conspectus of the native and naturalized species of Nephrolepis (Nephrolepidaceae) in the world. Blumea 50: 279-322.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Nephrolepis brownii Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/nephrolepis-brownii/ (Date website was queried)