Asplenium obtusatum
Common names
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 40–300 mm long, dark brown at base, green above, stout, covered in ovate scales with acute or acuminate apices. Laminae ovate, 60–400 × 50–200 mm, dull green, very thick and fleshy, pinnate. Raches green, stout, prominently grooved and scaly. Pinnae 5–15 pairs, narrowly ovate to oblong, obtuse to acute, crenate-serrate to entire, cuneate at base, 10–100 × 10–25 mm, scaly on the underside. Sori up to 10 mm long, not reaching to lamina edge.
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 decurrens differs from A. obtusatum by its allopatric distribution, narrowly triangular scales, mostly smaller fronds, larger spores and octoploid chromosome number (2n = 288 cf. 2n = 144 in A. obtusatum).
Distribution
Indigenous. New Zealand: North Island (Cook Strait only), South Island, Chatham Islands, Stewart Island/Rakiura, Snares Islands/Tini Heke, Antipodes Islands, Auckland Islands and Campbell Island/Motu Ihupuku. Also South America as well as on many islands of the southern Atlantic and Pacific Oceans.
Habitat
A coastal fern confined in the northern part of its range to only the most exposed situations. Further south it grows not only on exposed cliffs but also in coastal vegetation where it often forms an important association with Veronica elliptica and Austroblechnum durum. Frequently associated with sea bird colonies.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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
Aspleniaceae
Synonyms
Asplenium obtusatum var. obliquum (G.Forst.) Hook.f.; Asplenium apice-dentatum Homb. et Jacq.; Asplenium lucidum var. obliquum (G.Forst.) Moore; Asplenium obtusatum G.Forst. subsp. obtusatum
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Propagation technique
Easily grown but generally rather slow. A spectacular pot plant. Thrives with added poultry manure, thus simulating its common habitat of coastal seabird colonies (Ogle 1987).
Other information
Cultivation
Occasionally available from plant and specialist native plant nurseries although some plants sold are A. decurrens.
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.
obtusatum: Obtuse, or blunt
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.
ASPOBT
Chromosome number
2n = 144
Previous conservation statuses
2017 | Not Threatened | Qualifiers: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
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.
Ogle CC. 1987: Taxonomic changes in Asplenium (Aspleniaceae; Filicales) in New Zealand. New Zealand Journal of Botany 25(4): 591–593. https://doi.org/10.1080/0028825X.1987.10410089.
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 obtusatum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/asplenium-obtusatum/ (Date website was queried)