The New Zealand Plant Conservation Network

Species

Tmesipteris tannensis

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

Common Name(s)

Fork Fern

Current Conservation Status

2012 - Not Threatened

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 - Not Threatened
2004 - Not Threatened

Authority

Tmesipteris tannensis (Spreng.) Bernh.

Family

Psilotaceae

Flora Category

Vascular - Native

NVS Species Code

TMETAN

Structural Class

Ferns

Synonyms

Lycopodium tannense Spreng.; Tmesipteris fowerakeri H.N.Barber, Tmesipteris forsteri sensu A.Cunn. nom. inv.,

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.

Threats

Not Threatened

Chromosome No.

2n = 208

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 19 Jan 2014