Hymenophyllum lyallii


Hymenophyllum: Membranous leaf, from the Greek humen and phullon
lyallii: Named after David Lyall (1817-1895), 19th century Scottish naturalist and surgeon with the Royal Navy, who explored Antarctica, New Zealand, the Arctic and North America and was a lifelong friend of Sir Joseph Hooker.

Common Name(s)

Filmy fern

Current Conservation Status

2012 - Not Threatened

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 - Not Threatened
2004 - Not Threatened


Hymenophyllum lyallii Hook. f.



Flora Category

Vascular - Native

NVS Species 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.

Structural Class



Sphaerocionium lyallii (Hook. f.) Hook. et Barker; Trichomanes lyallii (Hook.f.) Hook. ex Hook. et Baker;


Indigenous. New Zealand: North, South, Stewart, Chatham and Auckland Islands. Also Australia. From the Mangamuka Range and Ahipara south but mostly westerly and uncommon in the southern North Island.


Lowland to montane (mostly montane in northern part of range). Usually epiphytic (rarely on rocks or mosses banks) on tree fern trunks, or at the base of trees in cloud forest, or in root and trunk caves.


Epiphytic (rarely rupestral) diminutive fern. Rhizome long creeping, much branched, slender, filiform, 0.1-0.2 mm diameter, dark brown to black, glossy, hairy; hairs red-brown, simple or once-forked. Frond lamina 10-50 mm long. Stipe 10-70 mm long, filiform, wiry, widely spaced; hairs similar to those of rhizome, tufted near the base, scattered above. Lamina flabellate to almost round, divided into dichotomous segments, very rarely simple, deltoid to very broadly obovate or round, 5-40 mm long, 10-30 mm wide, dull green-black to glaucous-black, membranous; conventional laminal blades present. Ultimate segments 1-20, opposite, ascending, 0.8-11 mm long, 0.8-1.8 mm wide, glabrous; margins bearing small persistent teeth with fugacious simple or forked hairs. Sori marginal, solitary or rarely in pairs, at the apex of the ultimate segments, deeply sunken in the lamina; involucre obcordate or cuneate-obconical, sometimes bilabiate, 0.5-2.3 mm long, 0.8-2.5 mm wide, apex retuse, erose or toothed. each toothed bearing a reddish forked hair; receptacle included.

Similar Taxa

A very distinctive species that is nonetheless occasionally confused with reduced states of Hymenophyllum flabellatum (which has flabellate fronds) which has the rhizomes, base of the stipe copiously covered in yellow to yellow-white simple hairs (the same hairs may also be present on the abaxial surface of the fronds (especially immature expanding fronds)) and yellow-green to emerald green pinnae.



Flower Colours

No Flowers



Propagation Technique

Difficult - should not be removed from the wild


Not Threatened

Chromosome No.

2n = 72

Endemic Taxon


Endemic Genus


Endemic Family


Life Cycle and Dispersal

Minute spores are wind dispersed (Thorsen et al., 2009).

Where To Buy

Not commercially available


Fact Sheet Prepared for NZPCN by P.J. de Lange (11 April 2011). Description adapted from Bostock & Spokes (1998) and 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

Bostock, P.D.; Spokes, T.M. 1998: Hymenophyllaceae: Flora of Australia 48: 116-148.

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

This page last updated on 19 Jul 2015