Hymenophyllum bivalve
Common name
filmy fern
Synonyms
Meringium bivalve (G. Forst.) Copel.; Sphaerocionium bivalve (G.Forst.) C.Presl; Trichomanes bivalve G.Forst.; Hymenophyllum pyriforme Bosch; Hymenophyllum spathulatum Colenso
Family
Hymenophyllaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Ferns
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.
HYMBIV
Chromosome number
2n = 44
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Distribution
Indigenous. New Zealand: North, South, Stewart, Chatham and Auckland Islands. From Campbells Bay (Auckland) south, though scarce north of the Waikato. Also Australia (Queensland to New South Wales)
Habitat
Coastal to montane forest. Either terrestrial or a low epiphyte on tree trunks and exposed roots.
Features
Delicate, mat-forming terrestrial or low epiphytic fern. Rhizomes long-creeping, rather gracile, wiry, pliant, sparsely hairy; hairs dark brown, appressed. Frond pendulous in epiphytic plants otherwise with erect stipes and laminae lying horizontal. Stipes well spaced on rhizomes, 30-150(-180) mm long, slender, not-winged ± glabrous (sometimes with sparse hairs near base and apex); rachises narrowly winged throughout. Laminae 60-200 × 30-160 mm, light green, ± glabrous, broadly triangular to broadly ovate with apex deflexed, deeply 3-4-pinnate, primary pinnae often up-curved. Ultimate segments linear, 0.3-1.5 mm wide, obtuse, margins shallowly toothed. Sori numerous, terminating ultimate segments, slightly sunken in lamina, many on each primary pinna. Involucre round to ovoid, bilabiate, almost divided almost to base, 0.8-1.5 mm long, 0.5-1.5 mm wide; base cuneate, only slightly immersed; indusial flaps entire, smooth-edged; receptacle included or slightly exserted. Description adapted from Bostock & Spokes (1998) and Brownsey & Smith-Dodsworth (2000).
Similar taxa
Sterile plants are virtually impossible to distinguish from Hymenophyllum multifidum but when fertile this species is easily recognised by the much smaller sori which are held horizontally or slightly bent but never bent at 90 degrees to the plant of the frond as in H. multifidum. The fronds of H. bivalve are slightly larger than those of H. multifidum, brighter green, notably less prominently curled downwards, and the margins are more finely and less deeply toothed.
Flowering
N.A.
Flower colours
No flowers
Fruiting
N.A.
Life cycle
Minute spores are wind dispersed (Thorsen et al., 2009).
Propagation technique
Difficult - should not be removed from the wild
Etymology
hymenophyllum: Membranous leaf, from the Greek humen and phullon
Where to Buy
Not commercially available
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (17 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
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Hymenophyllum bivalve Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/hymenophyllum-bivalve/ (Date website was queried)