Acaena anserinifolia
Common names
bidibid, hutiwai, piripiri
Biostatus
Native – Endemic taxon
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
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
An evergreen dull green silvery herb, which spreads up to 1 metre or more across and about 15 cm in height. Found all over New Zealand in varied habitats. The pinnate leaves are sharply toothed and have hairs on the tips. The globe shaped flower balls are white, then grow into a cluster of hooked spikes, which when ripe brown off, become firm and may stick to your socks or laces when brushed past in order to disperse.
Flower colours
Red/Pink, White
Detailed description
Stoloniferous, prostrate, trailing and perennial herb, forming diffuse to dense patches up to 1 m diam. Stems 1–1.5 mm diameter, prostrate stems < 1 m long, erect stems < 150 mm long (unless scrambling up through surrounding vegetation, in which case taller). Leaves 10–75 mm long, stipules 3–8-fid, leaflets 9–13, oblong, 4–17 × 2–9 mm, 7–15-toothed to base, dull green to yellow-green, basal leaves often mottled brown, upper surface sparsely to densely hairy, undersides paler, glaucescent to silvery, and very silky hairy, teeth tipped with a tuft of brush-like hairs. Inflorescence scape 40–120 mm long, covered in long, appressed hairs. Capitulum 5–8 mm diam. at flowering, 10–20 mm diam. (including spines) at fruiting; florets c. 50-60; sepals 4; stamens 2; anthers white or rose; style 1; white; achene 1. Fruit obconic, 3 × 12 mm, hairy, spines 4, pale brown, 4–9 mm long, barbed.
Similar taxa
Often grows with Acaena novae-zelandiae but can be recognised by the distinctive tuft of brush-like hairs surmounting the leaf teeth apices. Undersides of leaves are distinctly silvery due to dense covering of appressed silky hairs. Acaena juvenca and A. emittens are closely related. Both can be easily recognised by their very gracile, slender, stems, rather diffuse foliage, by the distal 3–5 leaflets obovate and larger than the basal leaflets, and by the usually entire stipules.
Distribution
Endemic. Found throughout, Te Ika-a-Māui | North Island, Te Waipounamu | South Island, Rakiura | Stewart Island, and Rēkohu | Wharekauri | Chatham Island. Naturalised on the Auckland Islands and Motu Ihupuku | Campbell Island.
Habitat
Abundant from lowland to lower subalpine forest margins and in shrublands.
Detailed taxonomy
Genus
Family
Synonyms
Acaena pusilla (Bitter) Allan var. pusilla, A. pusilla var. suprasericascens Bitter, Acaena viridior (Cockayne) Allan. The names A. anserinifolia var. sericeinitens (Bitter) Allan and var. paucidens, are referrable to A. profundeincisa (Bitter) B.Macmillan.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
October–January
Fruiting
December–April
Life cycle and dispersal
Spiny hypanthia are dispersed by attaching to fur, feathers and clothing and possibly also dispersed by wind and granivory (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and from rooted pieces.
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]
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Other information
Etymology
acaena: From the Greek ‘akanthos’ thorn, referring to the spiny calyx that many species have
anserinifolia: With leaves like Potentilla anserina
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.
ACAANS
Chromosome number
2n = 42
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 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.
Otago: 2025 | Regionally Not Threatened
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Conservation Status of Indigenous Vascular Plants in Otago, 2025” Jarvie S et al. (2025) report.
Referencing and citations
References and further reading
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 by P.J. de Lange for NZPCN (1 June 2013)
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Acaena anserinifolia Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/acaena-anserinifolia/ (Date website was queried)