Thelypteris confluens

Common Name(s)

Marsh fern, swamp fern

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - At Risk - Declining
2004 - Gradual Decline


2012 - PD, TO
2009 - TO


Thelypteris confluens (Thunb.) C.V. Morton



Flora Category

Vascular - Native

NVS Species 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.

Structural Class



Pteris confluens Thunberg, Aspidium thelypteris var. squamigerum Schldl., Aspidium squamigerum (Schldl.) Fee., Thelypteris palustris var. squamigera (Schldl.) Weath., Thelypteris squamigera (Schldl.) Ching, Nephrodium squamulosum Hook.f., .


Indigenous. In New Zealand found in the North Island only from Te Paki to the Waitakere Ranges in the west and Bay of Plenty in the east. Mainly near the coast but extending inland within wetlands associated with geothermally active systems. Outside New Zealand reported widely from Africa, India and Australia but apparently now highly threatened and close to extinction in Australia.


Coastal, lowland and geothermally active eutrophic wetlands. Often found growing on the margins of lakes and slow flowing streams where it grows within "floating suds" that have developed from organic matter trapped amongst rafts of swamp millet grass (Isachne globosa) and raupo (Typha orientalis).


Long-rhizomatous, tufted fern. Often winter dormnant and summer-green in cooler habitats. Stipes 100-500 mm long, yellow-brown, wiry, clad in sparse scales. Fronds 150-350 x 50-130 mm, pale green, yellow-green to dark-green, stiffly erect, rather brittle, fertile fronds slightly smaller than sterile. Pinnae in 15-20(-30) pairs, the longest 30-70 x 7-12 mm, fertile shorter and narrower, divided almost to midrib into onlong, round-ended, ultimate segments. Indusia with sparse to dense glandular hairs.

Similar Taxa



Spore bearing fronds may be found throughout the year

Flower Colours

No Flowers


Spore bearing fronds may be found throughout the year

Propagation Technique

Easy from the division of whole plants and probably from fresh spores. Needs permanantly wet ground and does best in sunny sites within a pond or in partially submerged pots.


Formerly common in lowland coastal wetlands, this species remains abundant only inthose more remote western wetlands from the Kaipara Harbour north to Te Paki. It is close to extinction and highly threatened in the Bay of Plenty, with perhaps the largest populations now left on remote Matakana Island. The main threat seems to come from wetland drainage, eutrophication and the often associated spread of faster, taller growing weeds. The species is also popular with fern collectors, and some of the better known and more accessible populations have been depleted or destroyed through fern collection. According to the recent Australian Fern Flora treatment of this species the best populations in Australasia now occur in New Zealand. Its future is not assured in Australia.

Chromosome No.

2n = 70

Endemic Taxon


Endemic Genus


Endemic Family


Where To Buy

Not commercially available.


Fact sheet prepared for NZPCN by P.J. de Lange (21 April 2011). Description adapted from Brownsey & Smith-Dodsworth (2000).

References and further reading

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

Cameron, E.K., Bellingham, R.M. 1998. Thelypteris confluens an addition to the Waitakeres. Auckland Botanical Society Journal 53: 38.

This page last updated on 13 May 2014