Dicranopteris linearis
Biostatus
Native
Category
Vascular
Structural class
Ferns
Detailed description
Terrestrial fern. Rhizomes long-creeping, hairy. Fronds up to 0.3 m tall finely hairy with hairs irregularly branched; veins free. Stipes glaucous-brown to pale brown, persistent when dead, glabrous, terminated by a bud. Rachises of fronds in 1–2-tiers, forking 2–3 × at narrow angles with a bud terminating each fork, the ultimate branches pinnate, narrowly elliptic, 0.1–0.4 m long. Pinnae linear 10–40 × 2.5–5 mm, notched at apices, margins smooth, fused at base, pale green to yellow green to slightly glaucous green above, whitish to glaucescent below. Sori in one row either side of midrib and well away from pinna margins, comprising 6–10 pairs of sporangia, indusia absent.
Similar taxa
Distinguished from the distinctly related New Zealand species of Sticherus C.Presl and Gleichenia J.E.Smith by its hairyrather than scaly rhizomes, pinnae confined to ultimate branches rather than on all rachis branches, irregularly branched lamina hairs, and by the sporangia in groups of 6–10 rather than in groups of 2, 2–4 or in rows either side of the midrib. It is the only species of the New Zealand representatives of the family Gleicheniaceae to be completely confined to geothermal sites.
Distribution
Indigenous. New Zealand: North Island, where it grows on geothermally heated ground from Rotorua to Karapiti near Taupo. Widespread in tropics and subtropics.
Habitat
In New Zealand confined to geothermally active sites where it grows on heated soils, sinter field, and around geysers, hot pools, and steam vents.
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 | Threatened – Nationally Endangered | Qualifiers: RR, SO
Threats
Dicranopteris linearis is naturally confined to sites of geothermal acitivity within the Taupo Volcanic Zone. It is rather tolerant of extreme heat and able to withstand shading, and it has actively colonised newly created geothermal fields such as Karapiti. The population is considered to be stable now after significant historical decline. Its 2017 conservation status of Threatened – Nationally Endangered is based on the historical decline to what is now a very small area of occupancy. It is possible some smaller populations might be threatened by introduced weeds tolerant of heated soils but there is no hard evidence available to confirm this.
Detailed taxonomy
Family
Synonyms
Gleichenia linearis (Burm. f.) C.B. Clarke; Polypodium lineare Bruman, Polypodium dichotomum Thunb., Mertensia dichotoma Willd.
Taxonomic notes
New Zealand plants appear to represent a distinct cytorace. This needs further investigation.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Propagation technique
Easy from rooted pieces. Once established grows quickly. Prefers a sunny site in damp soil. Frost and cold sensitive.
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
Etymology
linearis: Linear (leaves)
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.
DICLIN
Chromosome number
2n = c.160
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 | Threatened – Nationally Endangered | Qualifiers: RR, SO
2012 | At Risk – Naturally Uncommon | Qualifiers: RR, SO
2009 | At Risk – Naturally Uncommon | Qualifiers: SO
2004 | Range Restricted
Referencing and citations
Attribution
Fact sheet prepared by P.J. de Lange for NZPCN (1 June 2013)
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Dicranopteris linearis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/dicranopteris-linearis/ (Date website was queried)