Tmesipteris tannensis
Common name
fork fern
Synonyms
Lycopodium tannense Spreng.; Tmesipteris fowerakeri H.N.Barber, Tmesipteris forsteri sensu A.Cunn. nom. inv.,
Family
Psilotaceae
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.
TMETAN
Chromosome number
2n = 208
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 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Distribution
Endemic. New Zealand, North, South, Stewart, Chatham and Auckland Islands.
Habitat
Coastal to subalpine.Terrestrial or epiphytic on a wide range of hosts and often sympatric with Tmesipteris elongata (less frequently with T. lanceolata and T. sigmatifolia). Less common in coastal and lowland areas in the far north where it is mostly known from higher altitude forest. However, steadily becoming more common from about Whangarei south.
Features
Rhizome: dichotomously branched, brittle, 2.0-3.5 mm diameter. Aerial shoot: developing over one to many years, but eventually terminating in a small appendage 0.1-0.5× the length of the largest leaves, simple, erect, suberect, or pendulous, 50-1200 mm long, triangular in cross-section, leaves and sporophylls spirally arranged. Leaves coriaceous, brittle, one surface deep glossy green, occasionally with a few stomata towards the far end, other surface dull green covered with stomata; shape variable often on same shoot, oblong, lanceolate, falcate, or ovate, 6-30 mm long × 2.5-9.0 mm broad; apex of leaf very variable often on the same plant, acute, obtuse to truncate, mucronate; mucro 1-2 mm long. Sporophylls: developed in regular or irregular zones or throughout most of the shoot except for the lowermost part, equal to or slightly shorter than the leaves; 5-7 per 10 mm of shoot. Synangium: 4.0-8.0 × 1.5-2.5 mm at point of attachment, biconic, persistent. Spores: yellow, released in a mass, anisopolar, bilateral, monolete, foveolate, concavo-convex, 67-92 × 27-45 microns broad (longitudinal plane).
Similar taxa
Easily distinguished from all other named New Zealand species of fork fern by the biconic synangia. An apparently unnamed species which may be endemic to Banks Peninsula is rather similar, differing mainly by its octoploid rather than tetraploid chromosome number and less distinctly biconic synangia. This form is in the process of being formally described and named.
Flowering
Not applicable - spore producing
Flower colours
No flowers
Fruiting
Not applicable - spore producing
Propagation technique
Difficult - should not be removed from the wild.
Etymology
tmesipteris: From the Greek tmesis (cutting) and pteris (fern), alluding to the forked appendages on fertile fronds
tannensis: Growing at Tanna, New Hebrides, where the species was first collected
Where To Buy
Not commercially available.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (June 2009). Description adapted from Chinnock (1975).
References and further reading
Chinnock, R.J. 1975: The New Zealand Species of Tmesipteris (Psilotaceae). New Zealand Journal of Botany 1: 743–768.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Tmesipteris tannensis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/tmesipteris-tannensis/ (Date website was queried)