None (described in 1991)
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 | Not Threatened | Qualifiers: Sp
Previous conservation statuses
2009 | At Risk – Naturally Uncommon
2004 | Range Restricted
Endemic. New Zealand: South Island (Central Otago and northern Southland - Crown, Pisa, Dunstan, Ida, Old Woman, and Old Man Ranges, Garvie and Umbrella Mountains)
Subalpine to alpine. In Chionochloa Zotov tussock grassland, around rock outcrops and between tussocks; also in induced Poa colensoi Hook.f. herbfield; herbfield close to seepages, and in fellfield.
Low-growing or mat-forming suffruticose perennial, with dark brown subterranean stems up to 2.5 mm diameter. Long shoots prostrate, rooting at nodes, c.10 cm long with internodes c.10 mm long; short shoots erect, c.20 mm long, c.1 mm diameter, pale brown, sparsely hairy. Leaves imbricate on short shoots, imparipinnate, 10-50 × 5-10 mm. Stipules 3-4 mm long, with margins and tips hairy, and free portion c.1 mm long, entire, triangular. Leaflets 3-5 pairs, gradually reduced in size to base of rachis, broad obovate or orbicular in outline, 2.5-5.0 × 2.5-4.0 mm, truncate at apex or slightly emarginate; upper surface glaucous, with sparse to moderately dense appressed hairs, and indistinct veins; lower surface glaucous, with appressed hairs on veins; teeth 6-9, dull red with pink hydathode area at tip, weakly penicillate. Hair simple, unicellular, 0.2-0.8 mm long, on stipules, rachis and leaflets. Capitulum terminating short shoot, sessile, subtended by several leafy bracts, 5-8 mm diameter at flowering, 25-35 mm diameter (including spines) at fruiting. Bracteoles on receptacle linear-lanceolate, c.2 mm long, with hairy margins. Florets c. 10, very shortly stipitate. Hypanthium c.1.5 × 1.5 mm, enclosing perigynous ovary, sparsely hairy, with 4 very short spines inserted third-way from apex. Sepals 4, arising from hypanthium rim, free or shortly joined at base, 1.5 mm long, ovate, thickened at tip, hairy below. Petals 0. Stamens 2-3; filaments up to 2.5 mm long; anthers 0.5 × 0.6 mm, white. Styles 2, 2.5 mm long including stigma; stigma white, fimbriate, 1 mm broad, protruding from aperture of hypanthium. Fruit indehiscent; achenes 2, enclosed in the hypanthium; hypanthium turbinate, c.2.5 × 2.0 mm, red-brown, 4-ribbed, sparsely hairy; spines 4, 5-20 mm long, red, softly sparsely hairy, at least when young, with a group of retrorse hairs at tip.
Allied to A. buchananii Hook. F. which differs from A. tesca by its lower altitudinal range, more compact growth habit, densely tufted leafy stems and pale milky green or grey foliage (rather than glaucous). Acaena buchananii has 5-6 imbricate cf. 3-5 pairs of basally remote leaflets, while the capitula of A. buchananii is compressed with spines held erect, rather than the loose ball and divergent spines typical of A. tesca.
February – March (- February)
Easily grown from fresh seed and from rooted pieces.
A Naturally Uncommon, sparsely distributed species which is at times locally abundant. There are no known threats.
acaena: From the Greek ‘akanthos’ thorn, referring to the spiny calyx that many species have
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