Acaena caesiiglauca
Common names
glaucus 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 | Not Threatened
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
An evergreen hairy silvery-blue herb, which spreads up to a 1 metre across and about 10cm in height. The pinnate leaves are delicate and toothed, and may have a pinkish, contrasting coloured margin. The globe shaped flower balls are white and 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
White
Detailed description
Stoloniferous, prostrate, trailing perennial herb, forming a loose mat up to 1 metre in diameter. Stems less than 2 mm diameter, hairy, up to 30 cm long, and/or 10 cm high, rooting at nodes; Stipules perfect to bifid; Leaves odd-pinnate, between 20-100 mm long with 7-9(-11) leaflets; Leaflets ovate with narrowing base, serrated toothed margin, teeth are hair-tipped, lower 1/3 untoothed, lower leaflets much smaller, distinctly bluish green on upper surface often with pink-purple-light brown coloured teeth, upper surface flat, almost hairless to very hairy, lower surface very hairy; Inflorescence scape up to 200 mm, very hairy; Capitulum of 50-70 florets, each floret has 4 sepals, 2 stamen, white anthers, 1 style, 1 achene; Fruit roughly cone-shaped, each having 4 barb-tipped spines, up to 7 mm long, which mature dry, pale brown when ripe, enabling attachment to passing hairy/feathered surfaces as vector, and/or to aid wind dispersal.
Similar taxa
Acaena fissistipula, another bluish-green species, stipules are 3-5-fid rather than perfect or bifid; leaflet teeth are rounded rather than sharply pointed; flower stems are almost hairless compared to hairy; anthers are red rather than white.
Acaena tesca, also glaucous in colour, rhizomatous rather than stoloniferous; capitulum lacking scape, rather than up to 200mm; spines of fruit up to 20 mm long rather than up to 7.5 mm, and red; confined to central Otago.
Acaena inermis, glaucous or dull purple-brown in colour, rhizomatous rather than stoloniferous; stipules entire only; up to 15 leaflets; leaflet teeth are rounded rather than sharply pointed, lack hairy tip; scape up to 75 mm, rather than up to 200 mm; only 20 florets at most per capitulum; fruit spikes red, lacking barbs or hairs.
Distribution
Endemic. South Island. East of main divide.
Habitat
Montane to alpine (600-1500 m.a.s.l.), tussock grassland and scree margins.
Threats
Declining in Otago the National Stronghold for this species.
Detailed taxonomy
Genus
Family
Synonyms
Acaena caesiiglauca var. pilosa (Kirk) Allan, Acaena sanguisorbae var. pilosa Kirk, Acaena sanguisorbae subsp. caesiiglauca Bitter
Taxonomic notes
In Allan (1961) and Mark (2012) a ‘var. pillosa’ is mentioned which is said to differ by having more numerous leaflets, 11-13, which are equally hairy above and below, this is suggested as a synonym in Webb et. al. (1988), as no type specimen was found.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November-January.
Fruiting
December-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
CULTIVATION
Often found as a decorative planting specimen in commercial nurseries.
Etymology
acaena: From the Greek ‘akanthos’ thorn, referring to the spiny calyx that many species have
caesiiglauca: From the Latin caesius ‘lavender blue’ and the Greek glaukos ‘sea green’
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.
ACACAE
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
Otago: 2025 | Regionally Not Threatened | Qualifiers: DPS, DPT, NStr
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 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. Government Printer, Wellington, NZ. pg. 360.
Jarvie S, Barkla J, Rance B, Rogers G, Ewans R, Thorsen M. 2024. Regional conservation status of indigenous vascular plants in Otago. Otago Regional Council, Otago Threat Classification Series, 2024/3
Lloyd K. 2001. A Key and notes for Acaena (Rosaceae) in New Zealand. Botanical Society of Otago Newsletter 25. Pgs.10-14.
Mark AF. 2012. Above the Treeline: A Nature Guide to Alpine New Zealand. Craig Potton Publishing, Nelson. pg.113.
Webb CJ, Sykes WR, Garnock-Jones PJ. 1988. Flora of New Zealand, Volume IV. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. Botany Division, Department of Scientific and Industrial Research, Christchurch, NZ. Pg. 1059.
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 MD Ward (August 29th 2025). Description adapted from Mark (2012), Lloyd (2001), Webb et. al. (1988), Allan (1961).
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.