Achnatherum petriei
Synonyms
Stipa petriei Buchanan
Family
Poaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Grasses
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.
ACHPET
Chromosome number
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.
2018 | At Risk – Declining
Previous conservation statuses
2012 | At Risk – Naturally Uncommon | Qualifiers: EF, Sp
2009 | At Risk – Naturally Uncommon | Qualifiers: CD
2004 | Range Restricted
Distribution
Endemic. South Island only from South Canterbury to Central Otago
Habitat
Montane to subalpine (up to 1000 m a.s.l.). On dry stony ground and on rock outcrops (especially limestone and schist).
Features
Erect, wiry, yellow-green to brownish-grey perennial frequently branching at nodes. Branching extravaginal; cataphylls short. Leaf-sheath to 30 mm, usually glabrous, sometimes retrorsely pubescent. Ligule to 0.5 mm, auriculate, auricular lobes to 1 mm long, symmetrical or asymmetrical, usually finely pubescent. Collar thickened, occasionally with a very small tuft of hairs. Leaf-blade to 300 x 0.8 mm, narrow, involute, rigid, acicular, undersides glabrous, upper surface bearing short, stiff, white hairs. Culm to 600 mm long, wiry, internodes smooth, nodes purple, glabrescent. Panicle to 250 mm long, narrow; rachis smooth below, scabrid above, branches and pedicels scabrid. Glumes ± equal, to 7 mm long, hyaline, glossy, pink-suffused, produced into an awn-like process up to 0.5 mm long, or split at apex, < awn column; lower 1-nerved, upper 3-nerved. Lemma to 5.0 mm long, cylindrical, 3-5-nerved, margins contiguous, fulvous, clothed in white, ± appressed hairs; coma to 0.5 mm long, lobes short and inconspicuous; awn to 40 mm long, ± straight or weakly 1-geniculate, short and stiffly hairy, column loose twisted to 10 mm in length, arista to 30 mm long. Pale = lemma, clothed in long white hairs, apex ciliate, 2-nerved. Callus short (to 0.3 mm long), oblique, hairs white, to 1 mm long. Lodicules 3, one usually emarginate, or entire, 1-nerved, to 1 mm. Anthers to 2.7 mm long, weakly penicillate and shortly caudate. Seed 2.5-3.5 mm; hilum linear.
Similar taxa
One of the five stipoid grass genera known in New Zealand. From the other four genera it is distinguished by the margins of the 3-nerved lemma contigious, by the persistent awn, and long hairs on the palea. From Achnatherum caudatum (Trin.) S.W.L.Jacobs et J.Everett it is distinguished by the extravaginal rather than intravaginal branching; by the upper surface of the leaf-blade clothed in hairs rather than finely prickle-toothed; by the glume nerves being obscure rather than conspicuous; by the completely hairy lemma (in A. caudatum the hairs are confined to the lemma keel and outer margin); by the minute, obscure rather than conspicuous coma; prominent long awn (40 cf. 20 mm long), and free flowering rather than mostly cleistogamous flowering habit.
Flowering
November - February
Fruiting
January - May
Life cycle
Floret dispersed by wind (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed and the division of whole plants. Requires full sun, and excellent drainage, on a fertile soil to grow well. Will not tolerate humidity or damp conditions.
Threats
Rather widespread but localised in its occurrences. Probably better qualifies as Sparse because this is a naturally biologically sparse species. However, its survival now also depends on effective weed control. In some parts of its range it might be at risk from the spread of wild thyme (Thymus vulgaris L.) and stonecrop (Sedum acre L.).
Etymology
petriei: Named after Donald Petrie (1846 -1925), Scottish born Otago botanist
Where To Buy
Not commercially available
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange June 2005. Description modified from Edgar and Connor (2000)
References and further reading
Edgar, E.; Connor, H.E. 2000: Flora of New Zealand. Vol. V. Grasses. Christchurch, Manaaki Whenua Press. 650 pp.
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 11(4): 285-309.