Asplenium decurrens
Common names
northern shore spleenwort
Biostatus
Native
Category
Vascular
Structural class
Ferns
Detailed description
Rhizome stout, often forming a hard woody mass above ground, bearing brown, shiny, ovate, acuminate scales up to 15 × 4 mm. Stipes 20–180 mm long, dark brown at base, green above, stout, covered in narrowly triangular scales with acute or acuminate apices. Laminae lanceolate to ovate, 40–200 × 20–70 mm, dull green, very thick and fleshy, pinnate. Raches green, stout, prominently grooved and scaly. Pinnae 4–18 pairs, narrowly ovate to oblong, obtuse to acute, crenate-serrate to entire, cuneate at base, 10–40 × 7–12 mm, scaly on the underside. Sori up to 10 mm long, not reaching to lamina edge. Spores (39)–45–52–(60) × (25)–29–33–(38) μm.
Similar taxa
Recognised by the penchant for exposed sea cliffs; by the simply pinnate, thick and fleshy fronds which are < 30 mm wide; by the stipe and rachis which is scaly; by the usually < 8 pairs of pinnae; and by the pinnae bearing scales on the underside only. Asplenium obtusatum differs from A. decurrens by its allopatric distribution, ovate scales, mostly larger fronds, smaller spores and tetraploid chromosome number (2n = 144 cf. 2n = 288 in A. decurrens).
Distribution
Indigenous. New Zealand: Kermadec Islands, Manawatāwhi / Three Kings Islands, North Island (from Te Paki to just south of the Tongaporutu River in the west and to Lottin point in the east). Also Australia.
Habitat
On coastal rocks or amongst petrel scrub especially in places exposed to salt spray.
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
Asplenium obtusatum subsp. northlandicum Brownsey, Asplenium northlandicum (Brownsey) Ogle, Asplenium sarmentosum Willd.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Propagation technique
Easily grown but generally rather slow. A spectacular pot plant.
Other information
Etymology
asplenium: From the Greek a- ‘without’ and splene ‘spleen’, a northern hemisphere species, the black spleenwort (Asplenium adiantum-nigrum), was once believed to be a cure for diseases of the spleen.
Chromosome number
2n = 288
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
Auckland: 2025 | At Risk – Regionally Naturally Uncommon | Qualifiers: DE, DPS, DPT, RR, Sp, TL
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Auckland conservation status information is sourced from the “Conservation status of vascular plant species in Tāmaki Makaurau / Auckland” Simpkins E et al. (2025) report.
Referencing and citations
References and further reading
Brownsey PJ. 1977. A taxonomic revision of the New Zealand species of Asplenium. New Zealand Journal of Botany 15(1): 39–86. https://doi.org/10.1080/0028825X.1977.10429618.
Attribution
Fact Sheet Prepared for NZPCN by: P.J. de Lange 29 August 2007. Description adapted from Brownsey (1977).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Asplenium decurrens Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/asplenium-decurrens/ (Date website was queried)