Hymenophyllum flabellatum
Common names
filmy fern
Biostatus
Native
Category
Vascular
Structural class
Ferns
Detailed description
Rhizome long creeping, wiry, branched, 0.3–0.8 mm diameter, tan-coloured, with opaque villous hairs but tomentose at the stipe junction. Fronds 20–80 mm long, peundulous, rarely suberect. Stipe wiry, flexuose, 8–20 mm long, unwinged, with scattered pale-white or yellow hairs extending along main rachis. Lamina yellow-green, very variable in size and shape, oblong-linear to ovate-lanceolate (dwarfed fronds often broadly deltoid to round), 20–270 × 10–65 mm; primary division pinnate in the lower part, deeply pinnatifid above; pinnae or primary laminal segments oblique, 1–2-pinnatifid, flabellate, ovate or rhombic. Ultimate segments linear, 0.5–2.2 mm wide, glabrous to glabrescent; margins entire, 1–2-cells thick, apex obtuse, occasionally emarginate. Sori numerous; involucre ovate to rotund, bilabiate to below the middle, 0.5–2.0 × 0.5–2.0 mm; base broadly and shallowly cuneate; margins entire; receptacle included or slightly exserted. (Description adapted from Bostock & Spokes (1998) and Brownsey & Smith-Dodsworth (2000)).
Similar taxa
Only likely to be confused with the montane to subalpine, much less common endemic Hymenophyllum rufescens, which is a much smaller plant (up to 50 mm long), with deltoid fronds whose pinnae are covered in reddish, long, flexuose hairs. Although Hymenophyllum flabellatum and H. rufescens are rarely found growing together, occasional intermediates have been found, some of which are suggestive that both species may at times hybridise.
Distribution
Indigenous. New Zealand: Kermadec Islands, North Island, South Island (except eastern part), Stewart Island/Rakiura, Chatham Islands, Antipodes Islands, Auckland Islands. Also Australia (Queensland, New South Wales, Victoria, Tasmania); Vanuatu, Fiji, Samoa and Tahiti.
Habitat
Coastal to montane forest. Often epiphytic, especially on tree fern trunks, but also on shaded or sheltered, damp rocks, cliff faces, and overhanging banks
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened | Qualifiers: SO
Detailed taxonomy
Family
Synonyms
Mecodium flabellatum (Labill.) Copel.; Hymenophyllum nitens R.Br.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Life cycle and dispersal
Minute spores are wind dispersed (Thorsen et al., 2009).
Propagation technique
Difficult—should not be removed from the wild.
Other information
Where to Buy
Not commercially available
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for September 2023 for the full story.
Etymology
hymenophyllum: Membranous leaf, from the Greek humen and phullon
flabellatum: Fan shaped; from the Latin flabellum; shape of the leaves
NVS 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.
HYMFLA
Chromosome number
2n = 72
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened | Qualifiers: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
Otago: 2024 | Regionally Not Threatened
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Auckland: 2025 | Regionally Not Threatened | Qualifiers: DPS, DPT
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Auckland conservation status information is sourced from the “Conservation status of vascular plant species in Tāmaki Makaurau / Auckland” Simpkins E et al. (2025) report.
Referencing and citations
References and further reading
Bostock PD, Spokes TM. 1998. Hymenophyllaceae. Flora of Australia 48, Ferns Gymnosperms and allied groups: 116–148. ABRS/CSIRO Victoria, Australia.
Brownsey PJ, Smith-Dodsworth JC. 2000. New Zealand Ferns and Allied Plants. David Bateman, Auckland, NZ. 168 p.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
Attribution
Fact Sheet Prepared for NZPCN by P.J. de Lange (July 2009). Description adapted from Bostock & Spokes (1998) and Brownsey & Smith-Dodsworth (2000).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Hymenophyllum flabellatum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/hymenophyllum-flabellatum/ (Date website was queried)