Deparia petersenii subsp. congrua
Biostatus
Native
Category
Vascular
Structural class
Ferns
Detailed description
Terrestrial unpleasantly aromatic ferns. Rhizome long-creeping, c. 5 mm diameter, scaly; scales brown, basifixed, thin, broad, entire and acuminate. Fronds crowded. Stipe 20–500 mm long, base scaly and swollen, faintly winged. Lamina 150–500 × 60–250 mm, yellow-green to green, 2–3-pinnate, groove of rachis not open at junctions with grooves of pinna midribs, brittle, pinnatifid and tapered apically;lower pinnae stalked; upper pinnae sessile; longest pinnae central, 70–100 × 15–25 mm, lobed almost to the veins. Lobes elliptic to ovate,oblong or broadly obtuse; apical part of pinnae drawn out into a lobed, tapered cauda; main rachis with numerous septate hairs; lower surface scaly; veins simple or forked. Sori elongate, medial on the veins, often paired back to back; indusium thin, entire.
Similar taxa
Deparia petersenii subsp. congrua is a distinctive and easily recognised fern which has little resemblance to other New Zealand ferns (indigenous and naturalised). The long creeping rhizomatous habit, brittle yellow-green to dark green scaly fronds, which have an unpleasant aroma when bruised and/or crushed are diagnostic. It is sometimes confused with Diplazium australe, with which it often grows, partly because both Diplazium and Deparia have sori arranged in a herringbone pattern, a pattern which may also lead to confusion with Asplenium. Both Deparia and Diplazium differ from Asplenium by the sori which are paired back-to-back along the veins. Diplazium differs from Deparia by its much larger, more divided, glabrous fronds and by the groove of the rachis which is open and confluent with the grooves of the pinna midribs (rather than not open at junctions with grooves of pinna midribs). Deparia petersenii is sometimes divided into two species, the indigenous D. petersenii subsp. congrua and endemic D. tenuifolia, the chief difference being that D. tenuifolia has a mostly tripinnate frond, primary pinnae which are ovate and secondary pinnae which are oblong and supposedly a darker green colour. However numerous gradations occur, including plants with bipinnate and tripinnate fronds on the same rhizome, and in cultivation D. tenuifolia type plants have provided unstable. On current evidence there seems no valid reason to maintain two species though some authors e.g., Brownsey & Smith-Dodsworth (2000) have retained both taxa.
Distribution
Indigenous. New Zealand: Kermadec Islands (Raoul Island), North Island (common from Te Paki to the southern Waikato and Bay of Plenty, thence less common but evidently expanding its range southwards), South Island (current southern limit is in the vicinity of Westport). Also Australia (eastern Queensland, eastern New South Wales and eastern Victoria), Malesia, Polynesia and Norfolk Island.
Habitat
Coastal to lowland (rarely montane). A weedy fern of river flats, distrubed forest, forest margins, rough pasture, willow car and urban situations. Prefers damp ground and/or semi-shade to heavy shade.
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 | Qualifiers: SO
Detailed taxonomy
Genus
Family
Synonyms
Athyrium japonicum sensu Allan (1961); Deparia tenuifolia (Kirk) M.Kato; Diplazium congruum Brack.; Diplazium japonicum sensu Cheeseman; Athyrium congruum (Brack.) Copel.; Athyrium japonicum sensu Dobbie
Taxonomic notes
Family follows Rothfels et al. (2012).
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Life cycle and dispersal
Minute spores are wind dispersed (Thorsen et al., 2009).
Propagation technique
An easily grown fern that is inclined to become weedy and aggressive in most garden situations. Deparia flourishes in a semi-shaded situation, planted in moist, fertile soil. However, it will tolerate a diversity of conditions. In cooler areas it has a semi deciduous habit, dying down in winter and resprouting in spring. It is very easily grown from the division of established plants and also by spore, and is often found as a natural arrival in suitable gardens—at least in the northern part of its New Zealand range.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Other information
Cultivation
Occasionally available from mainline and specialist native plant nurseries. Often a nursery plant pot contaminant.
Status notes
Deparia petersenii subsp. congrua is probably a relatively recent natural arrival that is still expanding its range. The common bipinnate form was first noted in the New Zealands flora in 1906 however the unstable tripinnate form, sometimes treated as a distinct species (D. tenuifolia) was first noted in New Zealand in the 1870s suggesting that there may have been two independent dispersal events, or that there is an endemic element to this species in New Zealand.
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.
DEPPSC
Chromosome number
2n = 164
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 | Qualifiers: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
Auckland: 2025 | Regionally Not Threatened | Qualifiers: DPS, DPT
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.
Jones DL. 1998. Athyriaceae. Flora of Australia 48, Ferns Gymnosperms and allied groups: 418–429. ABRS/CSIRO Victoria, Australia.
Rothfels CJ, Sundue MA, Kuo Li-Y, Larsson A, Kato M, Schuettpelz E, Pryer KM. 2012. A revised family-leve classification for eupolypod II ferns (Polypodiidae: Polypodiales). Taxon 61(3): 515–533. https://doi.org/10.1002/tax.613003.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (18 January 2012). Description adapted from Brownsey & Smith-Dodsworth (2000). Family follows Rothfels et al. (2012).