Asplenium chathamense
Common name
Chatham Island spleenwort
Synonyms
None (fescribed in 1985)
Family
Aspleniaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Ferns
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.
ASPCHA
Chromosome number
2n = 144
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | At Risk – Naturally Uncommon | Qualifiers: IE
Previous conservation statuses
2009 | At Risk – Naturally Uncommon | Qualifiers: IE
2004 | Range Restricted
Distribution
Endemic. Chatham Islands (Chatham, Pitt, Mangere, Little Mangere, South East, Star Keys, Forty-Fours, Rabbit Islands, and on most other smaller islets and rock stacks)
Habitat
Primarily found on coastal rocks and cliffs in rock crevices or on the ground. Also found in coastal scrub, open coastal forest and along creeksides.
Features
Rhizome short, erect, bearing blackish-brown subulate scales up to 25 × 3 mm. Stipes 50-350 mm long, 2-4 mm diameter, stiff, pale brown at the base, green above, bearing scattered subulate scales 1-4 mm long. Laminae elliptic or rhombic to ovate, 50-450 × 35-200 mm, dark shiny green on upper surface, lighter on undersurface, stiff, erect, glabrous except for a few scattered scales, bipinnate to often tripinnate at base. Rachis green, or occasionally pale brown on undersurface, bearing a few small scattered scales. Primary pinnae in 6-17 pairs, the upper ones narrowly elliptic to narrowly ovate decreasing regularly in size towards the apex, the lower ones narrowly ovate to ovate, the longest below the middle 25-150 × 10-70 mm. Secondary pinnae on the upper primary pinnae ± linear, undivided, with obtuse apices; those on the lower primary pinnae narrowly elliptic or ovate and divided into tertiary pinnae, the longest 10-60 × 6-20 mm. Tertiary pinnae usually linear, undivided, up to 10 × 2 mm, occasionally larger and divided into 2-4 ultimate segments, apices obtuse. Sori extending along ultimate pinnules, 2-10 mm long, margins of indusia entire. Spores 34-52 × 21-37 micrometre; perispores prominently winged, sometimes with a few ridges.
Similar taxa
Most similar to A. appendiculatum (Labill.) C.Presl. which is not known from the Chatham Islands. However, A. chathamense is a tetraploid species whereas A. appendiculatum is octoploid, and the spores of the two have a rather different pattern of ridges. On the Chatham Islands it is most similar to A. flaccidium G.Forst. from whivh it differs by its terrestrial habitat preferences, erect rather than pendulous, more heavily divided glossy fronds, much longer secondary pinnae, and rather larger spores (40.0-50.0 × 26-33 micro m cf. 36.0-43.0 × 23.0-26.5 micro m).
Flowering
Not applicable - spore producing
Flower colours
No flowers
Fruiting
Not applicable - spore producing
Life cycle
Minute spores are wind dispersed (Thorsen et al., 2009).
Propagation technique
Easy from spores and rooted pieces. Very attractive but can be rather slow growing. Best in a large pot or planted in a deep, rich, moist soil in semi-shade. Prone to getting scale infections.
Threats
Not Threatened. A naturally Uncommon, Range Restricted endemic abundant on all the main Chatham Islands and surrounding islets and rock stacks
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.
chathamense: From the Chathams
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange (3 February 2006). Description from Brownsey (1985)
References and further reading
Brownsey, P.J. 1985: Asplenium chathamense - a new fern species from the Chatham Islands, New Zealand New Zealand Journal of Botany 23: 135-140.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 2009 Vol. 11 No. 4 pp. 285-309
Citation
Please cite as: de Lange, P.J. (Year at time of access): Asplenium chathamense Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/asplenium-chathamense/ (Date website was queried)