Species

Ophioglossum petiolatum

Etymology

Ophioglossum: snake's tongue; from the Greek ophis and glossa; appearance of the fertile leaf

Common Name(s)

Stalked adder’s tongue fern

Current Conservation Status

2012 - Threatened - Nationally Critical

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 - Threatened - Nationally Critical
2004 - Threatened - Nationally Endangered

Qualifiers

2012 - RF, SO, Sp
2009 - RF, SO, Sp

Authority

Ophioglossum petiolatum Hook.

Family

Ophioglossaceae

Flora Category

Vascular - Native

NVS Species Code

OPHPET

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.

Structural Class

Ferns

Synonyms

Ophioglossum pedunculosum sensu Allan (1961), O. reticulatum L.

Distribution

Indigenous. Known from the Three Kings (Great (Manawa Tawhi) Island), North, South and the Chatham Islands. Not recently recorded from the South Island. Last recorded from Chatham (Rekohu) Island in 2007. Still present on Great (Manawa Tawhi) Island, and locally from Te Paki to Kawhia and Arohaki Lagoon. Probably now extinct at Hokio, near Levin. New Zealand plants appear to belong to a widespread and common tropical species which reaches its southern limits in this country.

Habitat

Recorded from coastal and lowland habitats. A seasonally dormant species of ephemeral wetlands, moist talus and grassy areas, sandy margins of coastal lagoons, herbfields near lake margins, swamps and streams, and damp hollows within podocarp forest. Plants are most conspicuous between spring and late summer, dying down in autumn and winter.

Features

Perennial, seasonally dormant, firmly fleshy plants forming extensive patches in ideal conditions. Rhizomes erect, glabrous, loosely covered in fleshy white to pale yellow sheaths. Roots fleshy, proliferous. Sterile blade on short stalk up to 30 mm long, yellow-green to dark green. Lamina of sterile blade 15-150 x 6-40 mm, yellow-green to dark green, broadly to narrowly ovate, elliptic, undivided, base truncate to slightly attenuate, venation usually darker than rest of lamina, distinctly reticulate. Fertile spike on stalk 40-200 mm long. Fertile spike 14-60 mm long, bearing 15-48 pairs of sequentially ripening, long-persistent sporangia.

Similar Taxa

Ophioglossum coriaceum A.Cunn. which is generally smaller and has a narrower, oval-shaped and stalk-less sterile blade. The fertile spike is much shorter and carries fewer (7–15) pairs of spore-bearing capsules. However the distinction is not quite as clear cut and some populations with the sterile blade form of O. coriaceum but sporangia pairs of up to 25 are known. Further work on the status of plants referred to O. petiolatum in New Zealand is needed (see comments by de Lange & Rolfe 2010).

Flowering

October - December

Flower Colours

No Flowers

Fruiting

November - January

Propagation Technique

Easily grown by the division of whole plants. Does best in a fertile soil kept permanently moist (but not saturated). Will tolerate full sun but does better in semi-shade. Intolerant of competition from taller faster growing plants and very vulnerable to slug and snail browsing. This species makes an interesting and unusual pot plant. So far most New Zealand plants that have been investigated in detail have proved sterile. The sterility of the plants examined brings into question the exact status of plants attributed to this species in New Zealand.

Threats

May be overwhelmed by other plants or pigs. Destruction of suitable habitat or taking over of habitat by adventive species more able to tolerate changing nutrient status or with greater competitive ability. In cultivation this species is devastated by exotic snails and slugs and this maybe one of the problems for the species in the wild. Plants from two populations (Opuatia and Hokio) proved to be sterile.

Chromosome No.

Meiosis irregular

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Where To Buy

Can be purchased from Oratia Native Plant Nurseries (info@oratianatives.co.nz).

Attribution

Fact sheet prepared by P.J. de Lange 2004 (Updated 21 March 2011). Description based on de Lange et al. (2010).

References and further reading

Brownsey, P.J. 1985. Ophioglossum petiolatum at Hokio beach. Wellington Botanical Society Bulletin,  42: 33-34

Brownsey, P.J.; Smith-Dodsworth, J.C. 2000: New Zealand Ferns and Allied Plants. Auckland, David Bateman

Chinnock, R.J. 1998: Ophioglossaceae. Flora of Australia 48: 99-109.

de Lange, P.J. 1988. Ophioglossum petiolatum Hook in a reserve near Kawhia. Wellington Botanical Society Bulletin,  44: 4-7

de Lange, P.J.; Heenan, P.B.; Norton, D.A.; Rolfe, J.R.; Sawyer, J.W.D. 2010: Threatened Plants of New Zealand, Christchurch, Canterbury University Press. 471pp.

de Lange, P.J.; Rolfe, J.R. 2010: New Zealand Indigenous Vascular Plant Checklist. Wellington, New Zealand Plant Conservation Network. 164pp.

This page last updated on 4 Sep 2013