Abrodictyum strictum
Common names
erect bristle fern
Biostatus
Native
Category
Vascular
Structural class
Ferns
Simplified description
Terrestrial or epiphytic filmy ferm. Plants solitary or growing in patches of many individuals. Fronds narrow up to 14 cm long (usually less). Fertile fronds with sori at bases of frond divisions, on short branches, tubular with a fine hair-like projection prominently exserted from tube.
Detailed description
Terrestrial tufted fern. Rhizomes short, stout, erect, bearing numerous red-brown hairs. Fronds dark green, ± erect, arcuate. Stipes 30–140 mm long. Rachises narrowly winged throughout. Laminae 60–200(–220) × 20–60 mm, narrowly elliptic, 3-pinnate, somewhat stiff and bristly. Primary and secondary pinnae stalked, imbricate; ultimate segments linear, each furnished with a single unbranched vein. Sori present near bases of lamina segments, stalked on short branches, several on each primary pinna. Indusia tubular, mouth slightly flared, receptacle exserted.
Similar taxa
Easily distinguished from other New Zealand members of Abrodicytum species by the short, erect rhizomes, and long, narrow rather stiff and bristly fronds with finely divided linear ultimate segments. Most often confused with young plants of the very different Leptopteris hymenophylloides from which it can be distinguished by the tubular indusia bearing hair-like exserted receptacles.
Distribution
Indigenous. New Zealand: North Island (from Te Paki south), South Island, Stewart Island/Rakiura and Chatham Islands. Mainly westerly on the two main islands of New Zealand. Extremely uncommon on the Chatham Islands where it is known only from two sites on Chatham Island (Rēkohu). Also present in New Caledonia (Zhao et al. 2024).
Habitat
Coastal to montane, in closed forest (at usually (but not exclusively) at higher elevations in the North Island), often in tree caves, and amongst exposed tree roots, in and around rock overhangs, cave entrances, and within pot holes in ephemeral streams, or on mossy logs and moss covered banks and ledges within stream systems. Occasionally on clay banks in gumland scrub.
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
Threats
Not Threatened. However, this species is biologically sparse and possibly merits listing as ‘At Risk-Naturally Uncommon’ with the qualifier “Sp” [Sparse].
Detailed taxonomy
Genus
Family
Synonyms
Trichomanes strictum Menzies ex Hook. et Grev.; Macroglena stricta (Hook. et Grev.) Copel.; Trichomanes leptophyllum A.Cunn.; Trichomanes rigidum var. strictum (Menzies ex Hook. et Grev.) Field,
Taxonomic notes
NZPCN now follows Ebihara et al. (2006) and Zhao et al. (2024) in recognising Abrodictyum as distinct from Trichomanes. Although Brownsey & Perrie (2016) rejected this idea, the generic segregation was adopted by the PPG I (2016) and is now widely followed throughout the world.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Propagation technique
Difficult—should not be removed from the wild.
Other information
Etymology
abrodictyum: From the Greek habros ‘delicate’, ‘pretty’ and diktyon ‘net’, literally “delicate net”
strictum: From the Latin strictus ‘upright, stiff’
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.
ABRSTR
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
Auckland: 2025 | Regionally Threatened – Regionally Endangered | Qualifiers: DPR, DPS, DPT, PF, RR
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Auckland conservation status information is sourced from the “Conservation status of vascular plant species in Tāmaki Makaurau / Auckland” Simpkins E et al. (2025) report.
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.
Brownsey PJ, Perrie LR. 2016. Hymenophyllaceae. In: Breitwieser I, Heenan PB, Wilton AD. Flora of New Zealand - Ferns and Lycophytes. Fascicle 15. Manaaki Whenua Press, Lincoln, NZ. https://doi.org/10.7931/B1QP4Z.
Ebihara A, Dubuisson, J-Y, Iwatsuki K, Hennequin S, Ito M. 2006. A taxonomic revision of the Hymenophyllaceae. Blumea 51: 2–57. https://doi.org/10.3767/000651906X622210.
Yanan Zhao, Elodie Boucheron-Dubuisson, Germinal Rouhan, Kunio Iwatsuki, Atsushi Ebihara, Sabine Hennequin & Jean-Yves Dubuisson (19 Nov 2024): Updated diversity and taxonomy of the fern genus Abrodictyum C. Presl (Hymenophyllaceae, Polypodiidae) in Asia, Australasia and Oceania. Botany Letters. DOI:
https://10.1080/23818107.2024.2417245
PPG 1: The Pteridophyte Phylogeny Group 2016. A community-derived classification for extant lycophytes and ferns. Journal of Systematics and Evolution 54: 563–603. https://doi.org/10.1111/jse.12229.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (21 April 2011). Description adapted from Brownsey & Smith-Dodsworth (2000).