Asplenium haurakiense
Common names
Hauraki Gulf spleenwort
Biostatus
Native
Category
Vascular
Structural class
Ferns
Flower colours
No flowers
Detailed description
Mostly terrestrial. Rhizome short, stout, erect, bearing dark brown ovate scales with very thick cell walls, up to 20 × 2 mm. Stipes 50–200 mm (or more) long, brown on underside, green above, firm and erect, sparingly covered in small ovate scales with very thick walls. Laminae oblong to elliptic, 100–400 (or more) × 40–200 mm, ± dull or more often glossy green, thick, leathery, stiff and erect, pinnate to bipinnate. Raches green, sparingly scaly. Pinnae in 5–20 (or more) pairs, linear to narrowly ovate, acuminate, long stalked, 20–150 × 5–20 mm; degree of dissection very variable, sometimes only divided into very short obtuse segments, sometimes pinnate. Pinnules oblong and obtuse to linear and acute, up to 8 × 2 mm; basal acroscopic pinnule frequently much longer than that next to it, up to 40 mm long, and itself pinnatifid. Sori submarginal, linear, 2–7 mm long. Spores (38)–43–49–(54) × (20)–26–31–(38) μm.
Similar taxa
Allied to Asplenium flaccidum G.Forst. from which it differs by its mostly terrestrial growth habit, restriction to coastal areas, octoploid (2n = 288) rather than tetraploid (2n = 144) chromosome number, ovate rhizome and stipe scales (with very thick cell walls); stiffly erect rather than pendulous, usually glossy green rather than dull green, oblong to elliptic fronds; by the basal acroscopic pinnule which is frequently much longer than that next to it, up to 40 mm long, and itself pinnatifid; and by the larger spores. Asplenium appendiculatum subsp. maritimum (Brownsey) Brownsey occupies similar coastal habitats and is somewhat similar. It can be distinguished from A. haurakiense by its allopatric distribution, and by the lack of a greatly elongated basal acroscopic pinnule on each pinna.
Distribution
Endemic. New Zealand, Manawatāwhi / Three Kings Islands, North Island (northern areas to Waitakere coastline in the west and Moutohoura (Whale) Island in the east.
Habitat
Strictly coastal. Mostly terrestrial, growing in exposed or sheltered sites, often in positions subject to salt spray, also in petrel scrub and on small offshore islands it frequently grows around petrel burrows in dense forest.
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
Detailed taxonomy
Family
Aspleniaceae
Synonyms
Asplenium flaccidium subsp. haurakiense Brownsey
Taxonomic notes
Brownsey (1977) treated this fern as a subspecies. However, it is frequently sympatric with A. flaccidium s.s., and on occasion hybridises with it, producing sterile hybrids. Accordingly NZPCN prefer species rank. Kermadec Island group plants referred to A. flaccidium are perhaps closer to A. haurakiense. Further study is needed.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Life cycle and dispersal
Healthy plants produce spores throughout the year. Minute spores are wind dispersed (Thorsen et al., 2009).
Propagation technique
Easily grown. A very attractive fern which can be rather slow growing. Best in a large pot or planted in a deep, rich, moist soil in semi-shade. Prone to scale and mealy bug infections. A very variable species which could benefit from critical horticultural selection.
Other information
Cultivation
Occasionally sold by plant and specialist native plant nurseries.
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.
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.
ASPHAU
Chromosome number
2n = 288
Previous conservation statuses
2017 | Not Threatened
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.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
Attribution
Description modified from Brownsey (1977)