Species
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
Qualifiers
2012 - PD, TO
2009 - TO
Authority
Thelypteris confluens (Thunb.) C.V. Morton
Family
Thelypteridaceae
Flora Category
Vascular - Native
THECON
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
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., .
Distribution
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.
Habitat
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).
Features
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
None
Flowering
Spore bearing fronds may be found throughout the year
Flower Colours
No Flowers
Fruiting
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.
Threats
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
No
Endemic Genus
No
Endemic Family
No
This page last updated on 13 May 2014