Hymenophyllum armstrongii


Hymenophyllum: Membranous leaf, from the Greek humen and phullon
armstrongii: Named either after Joseph Francis Armstrong (1820-1902) or his son John Beattie Armstrong (1850-1926).

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 armstrongii (Baker) Kirk



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



Craspedophyllum armstrongii (Baker) Copel.; Hymenophyllum cheesemanii var. armstrongii (Baker) Cheeseman; Hymenophyllum melanocheilos Colenso; Microtrichomanes armstrongii (Baker) Copel.; Trichomanes armstrongii Baker in Hook. et Baker; Craspedophyllum cheesemanii (Baker) N.A.Wakef.; Hymenophyllum cheesemanii Baker in Hook.f.


Coastal to montane (in the North Island almost strictly montane), but extending to lowland and coastal areas in the western South Island and Stewart Island. Usually in closed forest where it is typically seen as a high epiphyte on tree trunks and branches often growing intermingled within epiphytic mat-forming mosses such as Macromitrium. Also found on damp rocks and cliff faces.


Diminutive, mat-forming fern. Rhizomes long-creeping, gracile, pliant, brittle when dry. Stipes 1-10 mm long, glabrous, membranous, not winged. Laminae oblong, undivided or forked 1-2×, 5-20 × 1-3 mm, dark green with conspicuous black midribs, glabrous, margins usually black, bearing prominent spines. Sori conspicuous, terminal, slightly sunken into lamina. Indusial flaps smooth-edged. Description adapted from Brownsey & Smith-Dodsworth.

Similar Taxa

A distinctive species readily distinguished from all other filmy ferns by its small size, oblong undivided or sparingly divided, dark green fronds with dark black midrib and spiny margins, and by the slightly sunken terminal sori.



Flower Colours

No Flowers



Propagation Technique

Difficult - should not be removed from the wild.

Chromosome No.

2n = 26

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 (17 April 2011). Description adapted from Brownsey & Smith-Dodsworth.

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

This page last updated on 10 Apr 2015