fossil fern, fork fern
Tmesipteris tannensis var. elongata Sahni
Vascular – Native
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.
2n = 208
Current conservation status
The threat classification 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) – more information about this can be found on the NZTCS website 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. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2017 | Not Threatened | Qualifiers: SO
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Sparse
Indigenous. North and South Islands. In the North Island recorded from Te Paki south to about Thames in the east and near Wanganui in the west. In the South Island recorded from Nelson, north-west Nelson and Westland. Present also in New Caledonia.
Coastal and lowland forest. Usually epiphytic on tree fern trunks but also found growing terrestrially in deep leaf litter. In the northern part of its range it grows mostly within kauri (Agathis australis (D.Don.) Lindl.) forest.
Plants usually epiphytic sometimes terrestrial. Rhizomes far-creeping, buried within host bark or tissue, or buried within leaf litter, branched, lacking roots. Aerial stems pendulous, 60-280 mm long, undivided. Lamina spirally arranged, 10-20 mm long, bright green to dark green, distinctly sigmoid or narrow-oblong, coriaceous, apices blunt, midrib distinct, prolonged beyond lamina as a fine mucro. Sporangia (synangia) yellow-green, confined to the base of the upper side of the lamina, somewhat inconspicuous, unequal, testiculate with rounded apices, usually confined to upper portion of stem.
Distinguished from the other New Zealand species by the sigmoid (sigma-shaped), mucronate, leaf-like lamina and small, rather inconspicuous, unequally sized, testiculate pairs of sporangia.
Not applicable - spore producing
Not applicable - spore producing
Difficult - should not be removed from the wild
A naturally uncommon and biologically sparse species. It is never common at any particular site and is often known from only a few specimens over wide parts of its range. It would be fair to say that it is undercollected and so in part our knowledge of this species is inadequate. Nevertheless it does not seem to be threatened, partly because it requires mature forest, much of which is already protected over large parts of its known range.
tmesipteris: From the Greek tmesis (cutting) and pteris (fern), alluding to the forked appendages on fertile fronds
Where To Buy
Not commercially available
Fact sheet prepared for NZPCN by P.J. de Lange (June 2009). Description adpated from Chinnock (1975).
References and further reading
Chinnock, R.J. 1975: The New Zealand species of Tmesipteris (Psilotaceae). New Zealand Journal of Botany 13: 743-768
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Tmesipteris sigmatifolia Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/tmesipteris-sigmatifolia/ (Date website was queried)