Pteridium esculentum
Common names
bracken, rarauhe, bracken fern
Biostatus
Native
Category
Vascular
Structural class
Ferns
Flower colours
No flowers
Detailed description
Fern with deeply rooted, subterranean rhizomes. Stipes and rachis chestnut brown at base, yellow-brown to russet at apex, woody, grooved, smooth, bearing sparse non-glandular hairs or ± glabrous stipe 0.2–1.3–(2.0) m or more long, 3–8–(15) mm diameter, woody. Lamina broadly elliptic or broadly ovate, 0.25–1.5–1.8 × 0.2–1.0–1.4 m wide, 3–4-pinnate at base, dark green (often glaucescent) above, paler beneath, adaxially glabrous, abaxially with sparse red-brown hairs on midribs and dense colourless appressed non-glandular hairs along veins. Longest pinnae arising at narrow angles; longest 150–650 × 80–400 mm. Secondary pinnae arising at narrow angles; longest 50–260 × 15–130 mm; basal one often much-reduced; midribs of primary and secondary pinnae narrowly winged. Tertiary pinnae decreasing markedly in length along secondary pinnae; longest 7–70 × 2–20 mm, with winged midribs. Quaternary pinnae to 12 × 4 mm; ultimate pinnules linear, straight, acute, entire, adnate and decurrent on 1 side. Sori continuous along pinna margin. Indusium > 0.2 mm wide, membranous, entire, glabrous. Spores dark yellow to orange yellow., granulose.
Similar taxa
A distinctive species which could not be confused with any other indigenous, naturalised or exotic fern present in New Zealand.
Distribution
Indigenous: New Zealand: Kermadec (Raoul Island only), North Island, South Island, Stewart Island/Rakiura, Chatham Islands and Antipodes Islands. Also South East Asia, Australia, Lord Howe, Norfolk Islands extending into western Oceania.
Habitat
Common in mainly seral habitats from the coast to the low alpine zone.
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 | Not Threatened | Qualifiers: SO
Detailed taxonomy
Family
Synonyms
Pteridium aquilinum var. esculentum (G.Forst.) Kuhn
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
None (spore bearing)
Fruiting
None (spore bearing)
Propagation technique
Despite its weedy nature this species is actually surprisingly difficult to grow from spores and/or transplants of young or mature plants. Best results seem to be from plants which spontaneously arise as pot contaminants within nurseries.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Other information
Cultivation
Rarely if ever, deliberately cultivated. Does not appear to be commercially available.
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for August 2017 for the full story.
Etymology
pteridium: Like Pteris; a fern known to the ancient Greeks; from the Greek pteris
esculentum: Edible; from the Latin esca and edere; in recognition of its value to the maori as a food plant
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
PTEESC
Chromosome number
2n = 104
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 | Not Threatened | Qualifiers: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | Regionally Not Threatened
Referencing and citations
References and further reading
Brownsey PJ. 1998. Dennstaedtiaceae: Flora of Australia 48: 214–228.
Brownsey PJ, Smith-Dodsworth JC. 2000. New Zealand Ferns and Allied Plants. David Bateman, Auckland, NZ. 168 p.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange 11 January 2011. Description adapted from Brownsey (1998) and Brownsey & Smith-Dodsworth (2000).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pteridium esculentum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pteridium-esculentum/ (Date website was queried)