Agrostis oresbia


Agrostis: Greek name for a kind of grass

Common Name(s)

mountain bent

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - Sparse


2012 - DP, Sp


Agrostis oresbia Edgar



Flora Category

Vascular - Native

NVS Species 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.

Structural Class





Endemic. North Island (Raukumara, Ruahine and Tararua Ranges). South Island, North-West Nelson (Lake Aorere and Mt Domett only)


A subalpine to alpine species frequenting damp seepages and water courses within tussock grassland and on rocky ground, shaded cliff faces or screes, occasionally on river flats.


Tufted or stoloniferous plants 50-250 mm, culms overtopping leaves. Leaf-sheath hyaline, light green to light brown, prominently ribbed, smooth, rarely with prickle teeth. Ligule 1-4.5 mm, truncate to obtuse, denticulate or entire, glabrous. Leaf-blade 20-70 x 1.5-2 mm, flat or folded, undersides smooth, upper prominently ribbed, margins usually smooth, sometimes sparsely to densely, scabrid, apex tapered, blunt, scabrid. Culm erect, internodes glabrous. Panicle (15-)20-60 mm, open, lax, oblong to pyramidal, with spreading or flexuous branches; rachis smooth, branches and pedicels smooth or scabrid. Spikelets 2-2.5(-3) mm, purplish. Glumes unequal, acute to acuminate, keel scabrid near apex, margins smooth, sometimes scabrid near apex; lower, 2-2.5(-3) mm, ovate-lanceolate, upper 1.7-2.5(-3) mm, elliptic-lanceolate. Lemma 1.5-2 mm, glabrous, faintly 5-nerved, ovate, obtuse; awn (1.5-)2-3 mm, geniculate, slightly projecting beyond glumes. Callus with minute hairs. Anthers 0.4-0.9 mm.

Similar Taxa

A. oresbia could be confused with A. magellanica Lam. but it is a smaller plant in all respects. It is perhaps closest to A. muelleriana Vickery from which it differs by its larger, more open, and laxer panicle, and by the glumes which are less scabrid and papillose. A. oresbia has a somewhat similar appearance to A. personata Edgar, from which it can be distinguished by its intravaginal innovations; awned lemmas; and by the abaxially smooth ligules. Palea 0.5 mm, ovate.





Propagation Technique

Unknown but should be easy from fresh seed and rooted pieces


Not threatened but rather a naturally uncommon species of spradic occurrence which is why it has been listed

Endemic Taxon


Endemic Genus


Endemic Family


Life Cycle and Dispersal

Florets are dispersed by wind and water (Thorsen et al., 2009).


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 2009 Vol. 11 No. 4 pp. 285-309

This page last updated on 10 May 2014