Nephrolepis brownii
Common names
rough sword fern
Biostatus
Native
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | At Risk – Naturally Uncommon | Qualifiers: RR, SO
Category
Vascular
Structural class
Ferns
Detailed description
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 × 100–250 mm, dark green or yellow-green. Pinnae 40 or more pairs, the longest 50–150 × 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.
Similar taxa
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.
Distribution
Indigenous. Kermadec Islands (Dayrell Island, Raoul Island, Macauley Island, Curtis Island). 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.
Habitat
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 rapense subsp. kermadecense Sykes).
Threats
No apparent threats. 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.
Detailed taxonomy
Genus
Family
Synonyms
Nephrolepis hirsutula (G.Forst.) C.Presl auct. non. New Zealand authors, Nephrolepis exaltata (L.) Schott auct. non. New Zealand authors
Taxonomic notes
Plants from the Kermadecs have been variously referred to as Nephrolepis exaltata (L.) Schott and N. hirsutula (G.Forst) C.Presl. 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.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Propagation technique
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.
Other information
Etymology
nephrolepis: Kidney scale
Chromosome number
2n = 82
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | At Risk – Naturally Uncommon | Qualifiers: RR, SO
2012 | At Risk – Naturally Uncommon | Qualifiers: RR, SO
2009 | At Risk – Naturally Uncommon | Qualifiers: SO, OL
2004 | Range Restricted
Referencing and citations
References and further reading
Brownsey PJ, Smith-Dodsworth JC. 2000. New Zealand Ferns and Allied Plants. David Bateman, Auckland, NZ. 168 p.
de Lange PJ. 2015. Recent vegetation succession and flora of Macauley Island, Southern Kermadec Islands. Bulletin of the Auckland Museum 20: 207–229.
de Lange PJ, Rolfe JR. 2010. New Zealand indigenous vascular plant checklist. New Zealand Plant Conservation Network, Wellington, NZ. 131 p.
de Lange PJ, Sawyer JWD, Rolfe JR. 2006. New Zealand indigenous vascular plant checklist. New Zealand Plant Conservation Network, Wellington, NZ. 94 p.
Hovenkamp, P.H.; Miyamoto, F. 2005: A conspectus of the native and naturalized species of Nephrolepis (Nephrolepidaceae) in the world. Blumea 50: 279-322.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange 10 August 2005. Description from Brownsey & Smith-Dodsworth (2000).
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)