Hymenophyllum pluviatile
Common names
filmy fern
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Ferns
Detailed description
Epiphytic, terrestrial or rupestral ferns. Rhizomes brown, long-creeping, 360–840 microns in diameter, glabrous or with colourless hairs clustered around stipe bases. Stipes brown to dark brown, 30–90 mm long, 330–800 μm diameter; wings poorly developed, often obvious only in the distal half of the stipe, with each wing usually less than 170 microns wide at mid-stipe and less than 500 μm at the stipe–rachis junction. Laminae 45–130 mm long, 20–67 mm wide; ovate or rarely triangular; apex attenuate to acute; base obtuse to truncate; green; glabrous; planate, or rachis wings and sometimes proximal axes flexuous; 4–5 pinnatifid, with 3–14–19 primary axes bearing quaternary axes, and the basal primary axis with 5–12 secondary axes bearing tertiary axes; primary pinnae 11–50 × 6–25 mm; axis-branching divaricate; segments entire, apices round or truncate, or sometimes shallowly emarginate. Sori orbicular or ovate. Indusial flaps 750–1340 × 660-1170 μm; apices round, truncate, or acute; apex usually irregularly dentate, or sometimes subentire.
Similar taxa
Hymenophyllum pluviatile is distinguished from H. flexuosum by its smaller size, narrower wings on the stipe and rachis, flatter lamina, narrower sori and usually irregularly dentate (cf. subentire) indusial flaps. Hymenophyllum pluviatile is distinguished from New Zealand populations of H. australe by its epiphytic, rupestral or terrestrial habitat (cf. growing in or around streams), its generally broader and more divided fronds, divaricating (cf. incurved) lamina axes, less developed stipe wings, and at most shallowly emarginate segment apices.
Distribution
Endemic. New Zealand: North Island and South Island from about the Waima Forest, Hokianga south, and mainly in the west
Habitat
Coastal to montane. Usually on base-rich rocks in dark but dry places—though often in the vicinity of waterfalls, streams or rivers. Sometimes epiphytic in cloud forest. This species is often found growing with Hymenophyllum demissum and H. flexuosum.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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 | At Risk – Naturally Uncommon | Qualifiers: DPS, DPT
Threats
An extremely uncommon and localised fern threatened by its small population sizes, and at one site—Mt Burnett—by dolomite mining. Previously regarded (as Hymenophyllum aff. flexuosum (AK 177370; Mt Burnett)) and treated either as ‘Sparse’ by de Lange et al. (2004) or ‘Naturally Uncommon’ by de Lange et al. (2009).
Detailed taxonomy
Family
Hymenophyllaceae
Synonyms
None - first described in 2013
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Propagation technique
Difficult—should not be removed from the wild
Other information
Etymology
hymenophyllum: Membranous leaf, from the Greek humen and phullon
pluviatile: From the Latin pluviatilis, meaning of rain or pertaining to rain.
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.
HYMPLU
Previous conservation statuses
2017 | At Risk – Naturally Uncommon | Qualifiers: DP, Sp
2009 | At Risk – Naturally Uncommon
2004 | Sparse
Referencing and citations
References and further reading
de Lange PJ, Norton DA, Heenan PB, Courtney SP, Molloy BPJ, Ogle CC, Rance BD, Johnson PN, Hitchmough R. 2004. Threatened and uncommon plants of New Zealand. New Zealand Journal of Botany 42(1): 45–76. https://doi.org/10.1080/0028825X.2004.9512890.
de Lange PJ, Norton DA, Courtney SP, Heenan PB, Barkla JW, Cameron EK, Hitchmough RA, Townsend AJ. 2009. Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47(1): 61–96. https://doi.org/10.1080/00288250909509794.
Perrie LR, Shepherd LD, de Lange PJ, Batty EL, Ohlsen DJ, Bayly MJ, Brownsey PJ. 2013. Hymenophyllum pluviatile, a new and uncommon fern from New Zealand. New Zealand Journal of Botany 51(4): 308–320. https://doi.org/10.1080/0028825X.2013.834830.
Attribution
Fact Sheet prepared by P.J. de Lange 11 December 2013. Description from Perrie et al. (2013)
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Hymenophyllum pluviatile Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/hymenophyllum-pluviatile/ (Date website was queried)