Acaena buchananii
Common names
bidibid, 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 | At Risk – Declining | Qualifiers: DPS, DPT
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
An evergreen dull milky grey/green herb, which grows in loose mats up to a 1 metre or so across amongst other vegetation, about 2 cm in height. The pinnate leaves are delicate and blunt-toothed, and hair tipped, the furthest leaflets being considerably larger. The stemless flowers are white in bloom and grow into a cluster of noticeable red or yellow hair tipped spikes, which when ripening become light brown or cream coloured.
Flower colours
Red/Pink, White
Detailed description
Rhizomatous; prostrate, trailing perennial herb, forming a loose mat up to 1 metre in diameter. Stems approximately 1.2 mm diameter, sparsely hairy, up to 10 cm long, and/or 2 cm high, rooting at nodes; Stipules entire, narrow; Leaves odd-pinnate, between 15-90 mm long with 11-13 leaflets; Leaflets egg-shaped, deeply serrated toothed margin, teeth blunt or rounded, 7-14 teeth per leaflet hair-tipped, lower leaflets smaller, distinctly dull milky-green, grey-green, grey-brown on both surfaces, veins and margins of lower surface hairy; Inflorescence scape no stem; Capitulum of approximately 10 florets, each floret has 4 sepals, 2 stamen, white anthers, 2 white styles, 2 achene; Fruit roughly cone-shaped, each having 4 hair-tipped (hairs backward facing) yellow or red spines, up to 15mm long, mature dry, pale brown to translucent cream when ripe.
Similar taxa
Perhaps closest to A. tesca from which it differs by its more compact growth form, with densely tufted leafy stems, pale milky green or grey foliage, by the almost imbricate 5-6 leaflet pairs, and by the compressed capitula with the yellow spines held erect.
Distribution
Endemic. Eastern South Island from Marlborough to Otago.
Habitat
Lowland to montane (10 - 800 m.a.s.l.), in short dry tussockland and turf, mainly in inland basins. In the drier parts of Central Otago it can be locally common especially in closely grazed non-improved pasture. Montane riverbeds and tussock grassland.
Threats
Habitat destruction through land development such as cultivation, oversowing, irrigation, orchard and vineyard establishment.
Detailed taxonomy
Genus
Family
Synonyms
Acaena buchananii var. picta Allan, A. buchananii var. inermis Bitter, A. depressa Kirk
Taxonomic notes
The status of A. buchananii var. picta (grey leaves and red spines) needs further study.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November-December.
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
Very easy from rooted pieces.
Other information
Etymology
acaena: From the Greek ‘akanthos’ thorn, referring to the spiny calyx that many species have
buchananii: Named after John Buchanan (13 October 1819-1898) who was a New Zealand botanist and scientific artist and fellow of the Linnean Society.
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.
ACABUC
Chromosome number
2n = c.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 | At Risk – Declining | Qualifiers: DP
2012 | At Risk – Declining | Qualifiers: DP
2009 | Not Threatened | Qualifiers: DP
2004 | Gradual Decline
Regional conservation statuses
Otago: 2025 | Regionally Threatened – Regionally Vulnerable | Qualifiers: DPS, DPT, NR, NStr, PF, Sp, TL
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
Allan HH. 1961. Flora of New Zealand, Volume I. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. Government Printer, Wellington, NZ. 1085 p.
Lloyd K. 2001. A Key and notes for Acaena (Rosaceae) in New Zealand. Botanical Society of Otago Newsletter 25. Pgs.10-14.
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.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange (1 August 2003).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Acaena buchananii Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/acaena-buchananii/ (Date website was queried)