The New Zealand Plant Conservation Network

Species

Asplenium chathamense

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

Common Name(s)

Chatham Island spleenwort

Current Conservation Status

2012 - At Risk - Naturally Uncommon

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - At Risk - Naturally Uncommon
2004 - Range Restricted

Qualifiers

2012 - IE
2009 - IE

Authority

Asplenium chathamense Brownsey

Family

Aspleniaceae

Flora Category

Vascular - Native

NVS Species Code

ASPCHA

Structural Class

Ferns

Synonyms

None (fescribed in 1985)

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

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

Chromosome No.

2n = 144

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Minute spores are wind dispersed (Thorsen et al., 2009).

This page last updated on 2 Mar 2017