Hymenophyllum flexuosum
Common names
filmy fern
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Ferns
Detailed description
Terrestrial or low epiphytic fern forming diffuse patches. Rhizomes long-creeping, thin, brittle. Fronds often widely spaced along rhizomes or in widely spaced aggregations. Stipes 30–110 mm long, slender, glabrous; stipes and rachises with a prominent broad, wavy-undulose, crisped wing running almost to stipe base. Laminae ovate 3–4-pinnate, 60–300 × 30–140 mm, bright green to yellow-green, glabrous. Ultimate segments oblong, margins smooth. Sori terminating ultimate segments, not sunken in lamina, solitary or paired, with many on each primary pinna. Indusial flaps with smooth margins. (Description adapted from Brownsey & Smith-Dodsworth (2000)).
Similar taxa
As both Hymenophyllum flexuosum and H. pluviatile grow together they are most likely to be confused. Hymenophyllum flexuosum differs from H. pluviatile by having lighter green, consistently crisped and crinkly fronds, with the stipe wing prominently crinkled. Hymenophyllum australe is only superficially similar, and its easily distinguished from H. flexuosum by its dark green-black strongly deltoid fronds, less distinctly crisped stipe wing and preference for rheophytic habitats.
Distribution
Endemic. New Zealand. North Island, South Island, Chatham Islands.
Habitat
Locally common in coastal to montane closed forest (coastal to montane in the North and Chatham Islands, confined to the lowland in the South Island). Usually found on boulders or rocks along waterways and in deeply shaded, rubble slopes but also frequently epiphytic on the plank roots and buttresses of pukatea (Laurelia novae-zelandiae) and maire tawake (Syzygium maire) in riparian forest. In the northern part of its range it is occasionally found growing with Hymenophyllum australe.
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
Detailed taxonomy
Family
Synonyms
Mecodium flexuosum (A. Cunn.) Copel.; Hymenophyllum australe var. flexuosum (A.Cunn.) C.Chr.
Endemic taxon
Yes
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
Etymology
hymenophyllum: Membranous leaf, from the Greek humen and phullon
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.
HYMFLE
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
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
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.
Otago: 2024 | Regionally Not Threatened
Referencing and citations
References and further reading
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 (18 April 2011). Description adapted from Brownsey & Smith-Dodsworth (2000).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Hymenophyllum flexuosum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/hymenophyllum-flexuosum/ (Date website was queried)