The New Zealand Plant Conservation Network

Species

Acaena tesca

Etymology

Acaena: From the Greek 'akanthos' thorn, referring to the spiny calyx that many species have

Common Name(s)

Bidibid, piripiri

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - At Risk - Naturally Uncommon
2004 - Range Restricted

Qualifiers

2012 - Sp

Authority

Acaena tesca B.H.Macmill.

Family

Rosaceae

Flora Category

Vascular - Native

NVS Species Code

ACATES

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

None (described in 1991)

Distribution

Endemic. New Zealand: South Island (Central Otago and northern Southland - Crown, Pisa, Dunstan, Ida, Old Woman, and Old Man Ranges, Garvie and Umbrella Mountains)

Habitat

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.

Features

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.

Similar Taxa

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.

Flowering

January

Flower Colours

White

Fruiting

February – March (- February)

Propagation Technique

Easily grown from fresh seed and from rooted pieces.

Threats

A Naturally Uncommon, sparsely distributed species which is at times locally abundant. There are no known threats.

Chromosome No.

2n = 42

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 29 Apr 2014