filmy fern, matua mauku
Mecodium dilatatum (G. Forst.) Copel.; Sphaerocionium dilatatum (G.Forst.) C.Presl; Trichomanes dilatatum G.Forst.; Diplooephyllum dilatatum (G.Forst.) Bosch; Leptocionium sororium C.Presl
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.
2n = 72
Current conservation status
The threat classification 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) – more information about this can be found on the NZTCS website 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. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2017 | Not Threatened
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Endemic, New Zealand: North, South, Stewart, Chatham and Auckland Islands. Widespread except for the drier parts of the eastern South Island.
Coastal to montane in forest. Usually epiphytic or on fallen logs and banks, Very rarely on the forest floor or on boulders.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland).
UPL: Obligate Upland
Rarely is a hydrophyte, almost always in uplands (non-wetlands).
Epiphytic (very rarely terrestrial) fern. Rhizomes long-creeping, gracile, wiry when fresh very brittle when dry. Stipes often widely spaced on rhizomes, 20-150(-200) mm long, stout, glabrous, distinctly though narrowly winged for part of length; rachises broadly winged throughout. laminae 80-400(-800) × 40-150(-160) mm, ovate, narrowly ovate to lanceolate, 3-4-pinnate, bright to dark green, glabrous. Ultimate segments rather broad, margins smooth, plane. Sori terminating ultimately segments, slightly sunk in lamina, many on each primary pinna. Indusial flaps smooth. Description adapted from Brownsey & Smith-Dodsworth (2000).
Easily distinguished from all other Hymenophyllum by the glabrous, smooth margined fronds; by the conspicuous broad, flat wing bordering much of the stipe and all of the rachis; and by the very broad pinnae.
Minute spores are wind dispersed (Thorsen et al., 2009).
Difficult - should not be removed from the wild
hymenophyllum: Membranous leaf, from the Greek humen and phullon
Where to Buy
Not commercially available
Fact sheet prepared for NZPCN by P.J. de Lange (17 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
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Hymenophyllum dilatatum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/hymenophyllum-dilatatum/ (Date website was queried)