Acaena magellanica
Common names
bidibid, piripiri, greater burnet, buzzy burr
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 Assessed
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
An evergreen sparsely hairy bluey/grey-green herb, which may spread over 10 metres across and about 15cm in height. The odd-pinnate leaves are bluntly toothed, with pink margins. The globe shaped red flower balls are held on a red stem and grow into a cluster of barbed 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, Purple, Violet/Purple
Detailed description
Stoloniferous, trailing perennial herb, prostrate stems 2-4 mm in diameter, forming a loose mat up to 10’s of metres in diameter. Stems up to 2 mm diameter, glabrous, up to 40 cm long, and/or 14-15 cm high; Stipules entire or bifid or trifid; Leaves odd-pinnate, between 20-120 mm long with 11-17 leaflets; Leaflets reduce gradually towards stem, oblong or obovate, serrated sharp toothed margin, 5-9 teeth per leaflet minutely hair-tipped or not, bluey/grey-green on upper surface paler below, teeth discoloured to pink or maroon, upper surface sparce hairs or glabrous, lower surface with fine shaggy hairs; Inflorescence scape 30-100 mm in flower, up to 210 mm when fruiting, red, glabrous or fine hairs; Capitulum of about 80-100 florets, each floret has 4-5 sepals, 2-4 stamen, dark red or purple/black anthers, 1 dark red style, 1 achene; Fruit roughly cone-shaped, each having 4 barb-tipped spines, up to 8 mm long, which mature dry, pale brown when ripe, tiny spines occasionally occur in between foremost spines.
Similar taxa
A native of Macquarie Island, not likely to be seen growing in New Zealand. On Macquarie Island it has been seen growing aside A. minor var. antarctica (the only other local Acaena species present), from which it can easily be distinguished by foliage colour, being bluey-grey/green compared to the light green of A. minor var. antarctica.
Distribution
Macquarie Island native with the New Zealand Botanical Region. Also found in South America, Falkland Islands, also other Sub-Antarctic Islands.
Habitat
Gravel, herbfield and fellfield.
Threats
This is a Macquarie Island endemic and occurs in the New Zealand Botanical Region but it is not encompassed by the New Zealand threat classification process as Macquarie is under the management of Australia.
Cats, rats, mice and rabbits introduced by sealers in the early 1800s posed a significant threat to sepcies endemic to Maquarie Island an when cats were initially erdaticated nearly a century later there was an explosion rabbits numbers. Further efforts were made to remove rodent perst by the Australian Government and in 2014 Macqurie was declared pest free.
Detailed taxonomy
Genus
Family
Synonyms
Acaena acroglochin Bitter, Acaena acutifida Bitter, Acaena adscendens Vahl, Acaena adscendens subsp. cardiostemon Bitter, Acaena adscendens subsp. georgiae-australis Bitter, Acaena adscendens var. glabriscapa Bitter, Acaena adscendens var. incisa Bitter, Acaena adscendens var. luxurians Bitter, Acaena adscendens var. macrochaeta Franch, Acaena adscendens var. majuscula Bitter, Acaena adscendens var. minuscula Bitter, Acaena adscendens var. pilosiscapa Bitter, Acaena adscendens var. semperpilosa Bitter, Acaena adscendens var. utrinqueglabrescens Bitter, Acaena affinis Hook.f., Acaena alboffii Macloskie, Acaena basibullata Bitter, Acaena brachyglochin Bitter, Acaena cadilla Hook.f., Acaena cadilla f. epistemonocoma Bitter, Acaena cadilla f. pusilla Bitter, Acaena calvivagina Bitter, Acaena canescens Phil., Acaena chamacaena Bitter, Acaena closiana Gay, Acaena colchaguensis Bitter, Acaena compacta Hauman, Acaena coxi Phil., Acaena decumbens (G.Forst. ex Gaertn.) D.W.H.Walton, Acaena depauperata Bitter, Acaena deserticola Phil., Acaena exaltata Bitter, Acaena floribunda Bitter, Acaena glandulifera Bitter, Acaena glandulifera subsp. nordenskjoeldii Bitter, Acaena glaucella Bitter, Acaena glaucophylla Bitter, Acaena grahamiana Gillies ex Walp. Acaena grandistipula Bitter, Acaena grossifolia Bitter, Acaena hirta Citerne, Acaena humilis Bitter, Acaena insularis Citerne, Acaena ischnostemon Bitter, Acaena krausei Phil., Acaena krausei subvar. glabratula Bitter, Acaena krausei var. massonandra Bitter, Acaena krausei var. meionandra Bitter, Acaena krausei subvar. pilosior Bitter. Acaena laevigata Reiche, Acaena laevigata W.T.Aiton, Acaena laevigata var. venulosa (Griseb.) Reiche, Acaena longiaristata H.Ross, Acaena longisepala Bitter, Acaena longistipula Bitter, Acaena macrophyes Bitter, Acaena macropoda Bitter, Acaena macrostemon Hook.f., Acaena macrostemon subsp. barbaticupula Bitter, Acaena macrostemon var. basipilosa Bitter, Acaena macrostemon subsp. closiana (Gay) Bitter, Acaena macrostemon subsp. latisepala Bitter, Acaena macrostemon subsp. longiaristata (H.Ross) Bitter, Acaena macrostemon subsp. longiplumosa Bitter, Acaena macrostemon subsp. pachystigma Bitter, Acaena macrostemon subsp. spectabilis Bitter, Acaena macrostemon var. supraconica Bitter, Acaena magellanica var. glabrescens Bitter, Acaena magellanica subsp. grandiscapa Bitter, Acaena magellanica subsp. laevigata (Aiton) Bitter, Acaena magellanica var. laevigata (Aiton) Citerne, Acaena magellanica var. pubescens Bitter, Acaena magellanica subsp. pygmaea Bitter, Acaena magellanica f. robusta Bitter, Acaena magellanica var. subtuspilosa Bitter, Acaena magellanica subsp. venulosa (Griseb.) Bitter, Acaena magellanica var. venulosa (Griseb.) Citerne, Acaena molliuscula Bitter, Acaena neglecta Bitter, Acaena novemdentata Bitter, Acaena nudicaulis Albov, Acaena obtusiloba Bitter, Acaena oligodonta Bitter, Acaena oligoglochin Bitter, Acaena oligoglochin var. dolichoglochin Bitter, Acaena oligomera Skottsb., Acaena ovalifolia var. cadilla (Hook.f.) Reiche, Acaena petiolulata Phil., Acaena philippii Gand., Acaena plioglochin Bitter, Acaena rubescens Bitter, Acaena sericascens Bitter, Acaena sericascens var. novemjuga Bitter, Acaena sericascens var. sexjuga Bitter, Acaena sericascens var. tenuibracteolata Bitter, Acaena subflaccida Bitter, Acaena subtusvillosula Bitter, Acaena tomentella Bitter, Acaena transitoria Bitter, Acaena trifida var. brachyphylla Bitter, Acaena triglochin Bitter, Acaena venulosa Griseb. in Abh., Ancistrum adscendens (Vahl) Poir, Ancistrum decumbens G.Forst. ex Gaertn, Ancistrum humile Pers., Ancistrum laevigatum Lag., Ancistrum magellanicum var. humile Pers. Poterium humile Lam.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
September-February.
Fruiting
November-May.
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)
Other information
Etymology
acaena: From the Greek ‘akanthos’ thorn, referring to the spiny calyx that many species have
magellanica: Named after the Magellan Straits in southern South America
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 Evaluated
2012 | Not Evaluated
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Allan HH. 1961. Flora of New Zealand. Volume 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledons. Government Printer, Wellington, NZ. Page 359.
Lloyd K. 2001. A Key and notes for Acaena (Rosaceae) in New Zealand. Botanical Society of Otago Newsletter 25. Pgs. 10-14.
Marticorena A. 2006. REVISIÓN DEL GÉNERO ACAENA (ROSACEAE) EN CHILE1. Annals of the Missouri Botanical Garden, 93(3): pp.412-454.
Marticorena AE, Cavieres LA. 2000. Acaena magellanica (Lam.) Vahl (Rosaceae). Gayana. Botánica, 57(1): pp.107-113.
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 2009 Vol. 11 No. 4 pp. 285-309
Attribution
Fact sheet prepared for NZPCN by MD Ward (August 29th 2025). Description adapted from Lloyd (2001), Allan (1961).