Stalked adder’s tongue fern
Ophioglossum pedunculosum sensu Allan (1961), O. reticulatum L.
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.
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 | Threatened – Nationally Critical | Qualifiers: RF, SO, Sp
Previous conservation statuses
2009 | Threatened – Nationally Critical | Qualifiers: RF, SO, Sp
2004 | Threatened – Nationally Endangered
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.
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.
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.
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).
October - December
November - January
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.
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.
ophioglossum: Snake’s tongue; from the Greek ophis and glossa; appearance of the fertile leaf
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.; 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.; 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.
Please cite as: de Lange, P.J. (Year at time of access): Ophioglossum petiolatum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/ophioglossum-petiolatum/ (Date website was queried)