Acaena microphylla var. microphylla Hook. f.q
Vascular – Native
Herbs - Dicotyledons other than Composites
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.
2n = 42
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Threatened – Nationally Critical | Qualifiers: OL
Previous conservation statuses
2009 | Threatened – Nationally Critical | Qualifiers: OL
2004 | Threatened – Nationally Critical
Endemic. North Island. North West Ruahine Range, where it is only known from ravines draining the Mangaohane Plateau and from the nearby Makirikiri Tarns.
Damp hollows within tussock grassland, and associated limestone ravines.
Stoloniferous, prostrate, perennial herb, forming dense patches. Prostrate stems c.70-250 mm long, rooting at nodes, erect stems 3-15 x 0.7 mm, brown, sparsely hairy. Leaves imparipinnate, 1-2(-5) x 5-12 mm. Stipules 2-4 mm long, margins and tips hairy, free portion 1 mm long, entire or bifid, acuminate, Leaflets 4-5, reducing in size toward base, suborbicular, 2-7 x 2-5 mm, truncate at apex; upper surface dull, pale olive, apple green or pinkish-purple, glabrous, veins distinct; lower surface paler, subglaucous; veins with appressed hairs; teeth 7-11, brown. Scapes 6-15 mm long at flowering, on short shoots hidden in foliage, densely hairy, scape bract 0 or 1, leaf-like. Capitulum 4-5 mm diam., 10 mm diam (including spines) at fruiting; florets c.10-12; sepals 4, stamens 2; styles 2; both white. Fruit 1.5 x 1.5 mm. Achenes 2, enclosed within turbinate, red-brown, 4-ribbed, hypanthium. Spines 0 or 1, 1-10(-15) mm long, pale red, tapered to naked tip.
Acaena microphylla Hook.f. is rather similar. This species has rich-green to greenish brown mottled foliage with shining cuticles, and scapes up to 250 mm long, which hold the capitula well above the foliage. As far as is known A. microphylla is not present in the North West Ruahine area.
Although exact flowering times are not known, plants have been seen in flower in April.
Although exact fruiting times are unknown plants have been seen in fruit in April.
Easily grown by division. This species rarely flowers in cultivation (at least within the North Island - although it has been reported that the species flowers each year in Dunedin) and it would seem that no one has yet tried to germinate seed.
Weed invasion by Pilosella spp., Agrostis spp. and hybridisation with Acaena anserinifolia.
acaena: From the Greek ‘akanthos’ thorn, referring to the spiny calyx that many species have
rorida: From the Latin meaning dewy, wet with dew
Fact sheet prepared for NZPCN by P.J. de Lange 1 October 2003. Description adapted from MacMillan (1991).
References and further reading
Macmillan, B.H. 1991: Acaena rorida and Acaena tesca (Rosaceae) — two new species from New Zealand. New Zealand Journal of Botany 29: 131-138
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
Please cite as: de Lange, P.J. (Year at time of access): Acaena rorida Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/acaena-rorida/ (Date website was queried)